eMac 800Mhz -> 1.33GHz conversion [Archive] - Page 2

SEN

Oct 31, 2004, 09:06 PM

Hello again,

I posted a while ago about clocking my 1ghz eMac up to 1.2ghz. I did have it running at 1.33 and 1.267 but I was experiencing problems with video encoding - blue artifacts would appear randomly throughout the video.

I brought it back to 1.2 and everything seemed fine.

Recently though, I bought Myst Revelation for OS X and I have noticed that
parts of the 'VR' navigation that contain moving video come out as all distorted - at points all the same colour. Maybe a bit hard to put into words, but definitely identifiable when seen.

The video in the VR navigation plays back perfectly across my iBook, Powerbook, B&W G3 and G3 iMac (albeit slow) - however gets distorted on my eMac (which is actually the fastest of the lot).

Wondering if it is a similar problem to what I was experiencing before. Anyone have this game to test out themself?

Brilliant game, BTW

madmaxmedia

Nov 2, 2004, 02:00 PM

These have a different CPU- the 7447, although I guess it's only a slight rev over the 7445. I actually bought it thinking it was the prior-year model since it was 1 Ghz, and was very pleasantly surprised to find out otherwise.

Has anyone tried to overclock this one? Or know if the jumpers would be the same? It would be sweet to be able to get to 1.4-1.6 Ghz or so someday, if I'm brave enough to try this (already have put in a 120 GB HD, DVD burner, and fan speed controller with Leo's awesome web page.)

If I could overclock it, then I'm basically getting the $1000 model for slightly more than half (the DVD burner only cost me $50 on EBay, and the 120 GB HD was $60 and is bigger than the 80 GB stock in the Superdrive model.)

I've noticed the refurb page on store.apple.com has current-gen 1 GHz emacs for $549 w/ cd-rom and $529 with no optical drives - these have the latest rev logic board (Radeon 9200, USB 2.0) but are clocked down to 1 GHz for edu-market sales.

For $550, it's tempting to pick one up just for hackin' - overclocking, modding into a headless case, etc.

Just a heads up for you modding types.

-vga4life

wernerru

Nov 2, 2004, 03:50 PM

These have a different CPU- the 7447, although I guess it's only a slight rev over the 7445. I actually bought it thinking it was the prior-year model since it was 1 Ghz, and was very pleasantly surprised to find out otherwise.

My 7445 is still running at 1.6ghz, and i just did a friends 7447-based emac, and kicked up to the same 1.6ghz. the great part is is the 167 fsb; we could up that as well, and take it to 2.0ghz. we did a regular oc to 2.0ghz, but it was unstable after about a few hours of semi-intensive work. it's rock-solid at 1.6ghz, running folding@home, which bashes the processor harder than any benchmarking utility.
best of luck
russ

madmaxmedia

Nov 2, 2004, 04:05 PM

Awesome, thanks! So would the directions for the 7445 work exactly the same for the 7447?

Great to know that I can kick my eMac up later, to better than new specs! (it already works great for me so far at 1 Ghz.)

My 7445 is still running at 1.6ghz, and i just did a friends 7447-based emac, and kicked up to the same 1.6ghz. the great part is is the 167 fsb; we could up that as well, and take it to 2.0ghz. we did a regular oc to 2.0ghz, but it was unstable after about a few hours of semi-intensive work. it's rock-solid at 1.6ghz, running folding@home, which bashes the processor harder than any benchmarking utility.
best of luck
russ

madmaxmedia

Nov 2, 2004, 04:09 PM

While it's better to be safe than sorry, here are some links I found regarding CRT discharge. I didn't discharge my CRT when I disassembled my eMac, but I left it unplugged for awhile just to be safe.

http://www.applefritter.com/thefritter/13/drwebster.html

So, if the danger is so low, why does Apple recommend discharging the CRT? Simple: lawyers. If Apple didn't give this advice, and someone simply claimed injury from a shock, then they'd have a problem, regardless of the facts. Plus, if you get zapped, maybe you'll slice your hand on something in reaction. It's a simple act of CYA for Apple to recommend always discharging the CRT.

A reasonable case could actually be made for why you should advocate *not* discharging a CRT routinely. If you require that everyone do so, then you're asking that everyone deliberately expose him- or herself to high voltage. One slip of the ground clip, and you get the honor of being the discharge path. If you really believe HV to be so dangerous, does this sound like good advice? And if you do fear an implosion, then does it make sense to require everyone to scrape a tool under the anode cup, potentially scoring the glass and weakening it to the point of causing an implosion?

And even if a discharge itself causes no bodily harm, it sure can cause delicate components on the circuit board to fry, depending on the particular path the discharge current happens to take.

So, here's a perfectly rational, safe policy: If you don't have to work on the high voltage supply, keep your cotton-pickin' mitts off of the high voltage circuitry. All the components there are very well insulated. And of course, always work on the Mac with the ac power disconnected (not just switched off; pull out the cord). If you want to minimize the chance of getting an unpleasant jolt, just let the thing sit overnight.

http://www.mail-archive.com/compact.macs@mail.maclaunch.com/msg12553.html

> Let's say if by accident my hand brushed up against the neck of the
> CRT, would I get a shock?

As long as you aren't working on the thing with power on, you're fine.
There are no exposed high-voltage parts on the crt. All the HV is *very* well
insulated. That's why you should ignore the standard advice to routinely discharge a compact mac's crt. You have to expose yourself to the HV nodes to discharge, and that just doesn't make sense if you're not going to do any work on the HV circuitry.

> How long should I wait for the CRT to discharge on its own if I don't
> use a tool?

Leave it unplugged overnight. Even without the fabled "bleeder resistor" in the
flyback transformer, the crt will discharge enough.

Really, the compact mac's cute little crt is not a thing to be feared.
:-) Don't allow the irrational (well-meaning, yes, but still irrational) warnings of others frighten you away from fixing these little guys. I hate to see a compact mac needlessly turn into landfill.

madmaxmedia

Nov 3, 2004, 06:52 PM

Here's an interesting program to overclock ATI video cards, all via software! (no soldering or even disassembling your computer.) It works for at least the most recent eMac (Radeon 9200)-

http://thomas.perrier.name/software/ATIcceleratorII.html

Here are some feedback reports from people who have tried this-

http://www.xlr8yourmac.com/Graphics/aticelleratorII_reports.html
http://morg.free.fr/atiacc2/index.php?lg=uk

It seems that increasing around 10% or so shouldn't be a sizeable risk. It's not too significant or anything, but it's an easy mod. Plus if you can get 10% higher FPS on Halo, etc., it might be worth it... ;-)

wernerru

Nov 4, 2004, 02:38 PM

Awesome, thanks! So would the directions for the 7445 work exactly the same for the 7447?

Great to know that I can kick my eMac up later, to better than new specs! (it already works great for me so far at 1 Ghz.)

Yeah, the 7447 as far as i remember went exactly the same as the 7445, just the FSB jumpers were in a different order (167 instead of 133). so a jump to the 12x like i did to go from 1.0 to 1.6, would take you to 2.0, which might not be stable, nor advisable :D . I'd say do a moderate jump, maybe to 10, which is what everyone is doing on the 133fsb.

madmaxmedia

Nov 4, 2004, 04:02 PM

Awesome, thanks for all the great information!

In reviewing the jumper settings-

http://www.freescale.com/files/32bit/doc/data_sheet/MPC7455EC.pdf (pg. 47)
http://www.lbodnar.dsl.pipex.com/eMac/eMac-upgrade.html

It looks like the 2 easiest overclocks for me would be 8x and 9.5x.
8x (giving me 1.3 Ghz) would only involve adding 1 jumper.
9.5x (giving me 1.58 Ghz) would only involve removing 1 jumper (great!)

As long as those are stable settings (I assume they are if 10x is stable), I'm thinking 9.5x would be better for me. I think this the speed you overclocked your friend's eMac at?

I have soldering experience but not much. I think I can handle removing 1 jumper, but would rather not have to remove and add multiple jumpers (giving me 5x as many opportunities to screw up.)

How hot does your overclocked eMac run? Like Leo, I added a fan controller to reduce the noise, but I'm wondering how low I can go if I overclock at 9.5x...I think the 7447 is probably comparable to the 7445, and Leo said the following about his overclocked eMac-

To cut the story short - you can slow down fan to the point where you cannot even hear it rotating and eMac would not care at all. Remember, this is with overclocked CPU, fast hard drive and 1GB or RAM and under day and night 100% load. If this is not the best computer hardware engineering, than what?!

I don't need to go so low as to not hear the fan. I don't know if he is using a bit of hyperbole in his statement though.

Thanks again,
Steve
(having lots of fun with a $550 eMac!)

Yeah, the 7447 as far as i remember went exactly the same as the 7445, just the FSB jumpers were in a different order (167 instead of 133). so a jump to the 12x like i did to go from 1.0 to 1.6, would take you to 2.0, which might not be stable, nor advisable :D . I'd say do a moderate jump, maybe to 10, which is what everyone is doing on the 133fsb.

wernerru

Nov 4, 2004, 06:02 PM

Awesome, thanks for all the great information!

As long as those are stable settings (I assume they are if 10x is stable), I'm thinking 9.5x would be better for me. I think this the speed you overclocked your friend's eMac at?
(having lots of fun with a $550 eMac!)

Yup, i took it to the 9.5, since soldering on dry pads is a huge pita. The temp really didn't increase much at all on either eMac tho. i'm almost thinking of getting a refurb myself, and oc'ing it to just have another mac

topgunn

Nov 5, 2004, 11:17 AM

Awesome, thanks! So would the directions for the 7445 work exactly the same for the 7447?

Great to know that I can kick my eMac up later, to better than new specs! (it already works great for me so far at 1 Ghz.)

I have both a 2nd and 3rd generation eMac. The 2nd gen was a 1GHz that i bumped up to 1.27GHz and the 3rd gen has remained at 1.25GHz, but not by choice. The first day I got it, I ripped it open to see if the layout of the logic board was similar enough to the 2nd gen to figure out the location of the PLL multiplier resistors. It wasn't and I have had zero luck trying to find them so far.

If anyone has any information that may help me find these pesky PLL resistors or even the FSB resistors, I would greatly appreciate the assistance.

Here is a link to some pictures I took of the logic board. http://www.texasgunns.com/emac . The first picture is where I would have expected to find the jumpers if the layouts between the 2nd and 3rd generations were similar.

Thanks,
John

madmaxmedia

Nov 5, 2004, 01:09 PM

Hmmmm, hopefully wernerru will be able to tell us exactly where they are.

A 1.25 Ghz CPU with 167 Mhz bus should mean a 7.5x multiplier. According to Leo's page (as well as the Motorola manual), the pattern of the jumpers should be '+ + + - +', where '+' means connected by a resistor.

BTW, I made a mistake regarding the 9.5x mod. It actually involves adding a jumper, in addition to removing one. Still not too much, and less work than 10x. It doesn't actually look that difficult to add a little solder to connect the jumpers.

topgunn

Nov 5, 2004, 01:49 PM

A 1.25 Ghz CPU with 167 Mhz bus should mean a 7.5x multiplier. According to Leo's page (as well as the Motorola manual), the pattern of the jumpers should be '+ + + - +', where '+' means connected by a resistor.

Yes, both my eMacs were factory set at a PLL multiplier of 7.5 and according to Freescale the jumper configuration is the same for both the 7445 and the 7447. The 2nd gen eMac is easy in that it has 5 jumpers in a wide open area that are in the same order as the PLL jumpers from the datasheets. However, not all macs have 5 resistors to change the multiplier. The 167MHZ FSB iMac uses 8 resistors to select the multiplier. Some older G4's only used 4. 98% of the pads on the PCB are occupied. There are probably on 4 or 5 locations where there are groups of unoccupied pads. This leads me to assume that one of the areas is the one that I need to concentrate on.

topgunn

Nov 7, 2004, 09:45 PM

Hmmmm, hopefully wernerru will be able to tell us exactly where they are.

Do you have any pictures of the jumper configuration of your eMac? If we look in the right areas we should be able to see some differences. Once I know which ones control the multiplier, I would be willing to do some trial and error testing.

Mechcozmo

Nov 8, 2004, 12:02 AM

madmaxmedia

Nov 8, 2004, 01:18 AM

Do you have any pictures of the jumper configuration of your eMac? If we look in the right areas we should be able to see some differences. Once I know which ones control the multiplier, I would be willing to do some trial and error testing.

Unfortunately I don't. I'm hoping we get good info from wernerru, since he has modded the exact same model as ours.

If we had no such info, I don't know if it would be too safe to try making changes without knowing exactly which are the right jumpers. Although it might be possible by process of elimination to find the exact right set.

Now I see that you have a 1.25 Ghz eMac. So if we compare photos and find which jumpers are different between our boards, we should know (and combined with the proper jumper settings for each of our multipliers.)

If we can't get any other info, I'd be willing to take apart my Mac and taking some photos. Let's give it a few days to see what comes up?

madmaxmedia

Nov 8, 2004, 01:20 AM

I just read the whole thing. Anyone wanna take a guess at how you could overclock an 800Mhz iMac? See my sig for more details on it. I'd like to at least widen the gap between it and obsoleteness. Very cool work... I'm gonna see if I can boost my brother's and sister's eMacs. :D

Search around on Google. I'm almost positive I saw overclocking directions for a G4 iMac, not sure if it was in English though or what the clock speed was. I think the directions I saw involved removing the heat sink in order to get to the jumpers.

brap

Nov 8, 2004, 01:26 AM

Search around on Google. I'm almost positive I saw overclocking directions for a G4 iMac, not sure if it was in English though or what the clock speed was. I think the directions I saw involved removing the heat sink in order to get to the jumpers.
Sure you don't mean this post, in this very thread (http://forums.macrumors.com/showpost.php?p=708009&postcount=149)?

SEN

Nov 8, 2004, 02:04 AM

http://www.swieskowski.net/icook/

"iCook is a small OS X kernel extension that allows simple overclocking..."

Is this kind of thing possible with other Apple models?

(turns out my graphics problems were/still are Myst, not the Mac)

jared_kipe

Nov 8, 2004, 02:10 AM

I made my girlfriend's (ok it's really mine) emac go from .8GHz to 1.4GHz and it booted fine. After like 30 min in Tiger woods (computer playing itself) it would die. So clocked it down to 1.33GHz and it would last 1 hour of greensome. So I (she) had to settle for 1.27GHz and a ATI video overclocker.

Mord

Nov 8, 2004, 11:26 AM

madmaxmedia

Nov 8, 2004, 01:39 PM

Sure you don't mean this post, in this very thread (http://forums.macrumors.com/showpost.php?p=708009&postcount=149)?

LOL, I didn't remember that post. I had also seen something else from the web somewhere...

"iCook is a small OS X kernel extension that allows simple overclocking..."

Is this kind of thing possible with other Apple models?

It's unlikely since this type of software clocking is built into notebook computers for energy conservation (besides being chip-specific.) I doubt any of the desktops have this ability.

Mord

Nov 9, 2004, 02:49 AM

[QUOTE=madmaxmediaI doubt any of the desktops have this ability.[/QUOTE]

all g5's have it and mosty powerbook's/ibooks

wernerru

Nov 10, 2004, 04:41 PM

Unfortunately I don't. I'm hoping we get good info from wernerru, since he has modded the exact same model as ours.

madmaxmedia, i tried to find the pictures i took when we did it, and i can't seem to find them tho. My friend now lives on the other coast, and he's not so tech-adept, so i can't ask him to take it apart and tell me. Sorry :o

madmaxmedia

Nov 10, 2004, 05:16 PM

madmaxmedia, i tried to find the pictures i took when we did it, and i can't seem to find them tho. My friend now lives on the other coast, and he's not so tech-adept, so i can't ask him to take it apart and tell me. Sorry :o

Thanks for the info. Was it hard to find the jumpers, or was the group hidden amongst a bunch of other jumpers?

It sounds like you were able to find them without some sort of reference telling you exactly where they were, which means that hopefully we can do the same thing.

It's not that hard to take apart an eMac! ;) I hope after I can overclock it, I'll never have take take off the cover again...

Thanks again for all your help,
MMM

wernerru

Nov 10, 2004, 07:34 PM

Thanks for the info. Was it hard to find the jumpers, or was the group hidden amongst a bunch of other jumpers?

mmm- i remember taking the heat-pipe off the processor, which means you need to get thermal paste to put it all back together. i think the jumpers were similar to the way the iMac g4 was laid out, with the jumpers being inside a little box that was printed onto the motherboard with teh r-numbers.
i'm still looking to see if i can find someone around here that has one i can take apart... no takers wanting a semi-stranger to take apart their mac so far :D

madmaxmedia

Nov 10, 2004, 11:49 PM

That would explain why topgunn couldn't find the right jumpers.

I imagine that you wouldn't have forgotten such a thing (whether you removed the heat sink or not), so probably that's what we'll have to do. Since there's not all that much room under the heat sink, it should be easy to locate the proper jumpers.

Is there some sort of clamp that holds the heat sink down? I installed a PC motherboard and CPU once, and there was a clamp that held the heat sink tightly to the CPU.

If it's similar, I imagine it wouldn't be too hard for me, as long as I prepared all the tools in advance (soldering iron, solder, thermal paste, I think that's it.)

Thanks!

madmaxmedia

Nov 11, 2004, 12:13 AM

Here's the link that I had mentioned previously about the G4 iMac. They don't have great luck, but everyone else seems to be able to go to 9.5x or 10x and run very stable.

http://www.ethernetworks.de/imac_g4_usb2_overclocking.html

In addition, we have this post earlier in this thread-

http://forums.macrumors.com/showpost.php?p=708009&postcount=149

The resistor numbers are different from the iMac to eMac, but I bet it will be easy to find the jumpers and figure out the right order based on what you currently are set at.

I'll try to give mine a go over the weekend if possible, and take some photos.

topgunn

Nov 12, 2004, 08:41 AM

mmm- i remember taking the heat-pipe off the processor, which means you need to get thermal paste to put it all back together. i think the jumpers were similar to the way the iMac g4 was laid out, with the jumpers being inside a little box that was printed onto the motherboard with teh r-numbers.
i'm still looking to see if i can find someone around here that has one i can take apart... no takers wanting a semi-stranger to take apart their mac so far :D

This is a photo taken underneath the heatsink on a 3rd generation eMac. There are only a few of these jumpers that are only accessible when the heatsink is removed and, at least on mine, there is no box similar to that on the 166MHz FSB iMac. Perhaps the PLL multiplier resistors are in a different location?

http://www.texasgunns.com/underheatsink.jpg

wernerru

Nov 12, 2004, 07:02 PM

very interesting... this looks like a different board revision than the one i took apart. anyway you can get a high-res board scan of both sides?
russ

topgunn

Nov 13, 2004, 12:26 AM

I won't be able to do that because my camera is only 2 MP and I have a hard enough time with pictures like the one above. Unless I could piece together multiple pictures (which would likely look like crap and be worth almost as much) it's just not possible.

By the way, when I try and take pictures of PCB, i have the dilema of using the flash and having the glare drown out everything in view or not using the flash and not having enough light to make out any detail. I have tried aiming the camera a severe angle to decrease the glare from the flash but then things are very distorted when taking close-ups. Any suggestions?

Mechcozmo

Nov 13, 2004, 02:11 AM

Any suggestions?

Yeahp. Use another light source, eg, desk lamp, from far enough away that it will light up the board but not drown it out. The key light for you people out there who are "in the know" about those things... ;)

wernerru

Dec 14, 2004, 10:27 PM

Kiss my A$$ fan noise! i just did it to my PC (yes, i unfortunately have a PC in here for class :( ), taking the main fan down to 7v instead of the full-bore 12v. The eMac fan seems to have a rheobus built in, but, when i plugged it into the PC ps, it just ran constant speed, regardless of what temperature i put by the sensor on the fan. I had a 3pin to 3pin extension sitting around, so i cut off one end, got rid of the sensor wire, and hooked up the wires to the outside 2 pins on the optical drive power connector (black to red, red to yellow), and bam, silent as hell. been running like this for a week now, no problems. now i hear the hard drive, but that's totally bearable, as i no longer have a jet engine running in my room 24/7! :D

jackdoe

Dec 26, 2004, 06:48 AM

This kinda ties in with running an eMac in another case...
I have an eMac with a smashed CRT, ideally I would like to use the guts of the machine in another case but failing that I would be content with just cutting power to the CRT and running an external.
A. Is this possible, or will the mac not output video to an external monitor if the internal is not powered up?
B. What wires do I need to eliminate to accomplish this? Or does the CRT get power directly from the down converter?

lbodnar

Dec 26, 2004, 08:10 AM

A. Is this possible, or will the mac not output video to an external monitor if the internal is not powered up?
B. What wires do I need to eliminate to accomplish this? Or does the CRT get power directly from the down converter?

A. No, eMac will not power up at all.

B. CRT PSU is pretty much independent, especially its HV part, however Apple implemented internal VESA link beween the logic board and CRT part using IVAD02 chip from ST (http://www.st.com/stonline/press/magazine/challeng/1stedi00/chal07.htm). Apart from standard 15-pin interface signals they also have I2C bus to control monitor adjsutments like distortion, geometry, etc.

So there are two options.

1. Keep IVAD module (shiny can attached to the end of the CRT) untouched and simply piggiback on RGB and sync signals outputting them to external monitor. You will be limited to only resolutions and sync frequencies supported by eMac screen.

2. Try properly connecting external monitor to all internal VESA signals and see if OpenFirmware will boot with it. Success depends on whether Apple hardcoded only one monitor type support into OF (or rather prohibited everything else.) You might need to keep or emulate I2C bus connection to IVAD.

Maybe the ultimate solution is to hack OF. This will also allow to boot modern Macs into OS9, etc.

Mechcozmo

Dec 26, 2004, 11:18 AM

Maybe the ultimate solution is to hack OF. This will also allow to boot modern Macs into OS9, etc.

Maybe it is... seeing as the screen-spanning hack does it, that is like hacking your OF. But isn't OF pretty much uncharted territory? Or if you have an ADC member ship, does that come with documentation?

jackdoe

Dec 30, 2004, 08:42 PM

Thanks for the replies. I'll see what I can do...

overlandparkmat

Jan 8, 2005, 06:57 PM

CubaTBird

Jan 9, 2005, 01:07 PM

this thread has been active for one year :eek:

x86isslow

Jan 12, 2005, 02:33 AM

Jigglelicious

Jan 12, 2005, 10:55 AM

so who's going to be brave an try oc'n the new minimac?

i'm really tempted to get one (i get edu pricing, so 470).

i figure that if i'm going to install ram myself, i might as well replace the HD and OC the proc.

If Apple is using the latest revision of the G4 (and they should be for heat reasons), then that processor should easily overclock to 1.5Ghz and beyond. The biggest issue would be keeping it cool inside that small enclosure. Still, it would be an interesting project for someone to undertake.

lbodnar

Jan 12, 2005, 11:09 AM

netjosh_granada

Jan 13, 2005, 07:15 AM

Hello to everyone,

I'm new to this forum but not to other technical forums and I have a BIG question:

I have a bunch of eMac 700 Digital Modules (Down converter, Logic Board, aluminium tray, cables, etc...) from a series of CRT-dead eMacs, but I DON'T have the Analog Modules (power converter) that provides the digital module all the voltages needed for the computer to work.

I've been thinking on using ATX power supplies to make them work but I need advice from all you "Pro" around here, because I'm planning on using these in a "Beowulf-like" cluster system in the office, and I have everything but the information on how it can be done.

I know that the Logic Board's "Blind-Mate" connectors provides all the electric connections, and on a previous post I saw that someone traced voltages on these "Blind-Mate" connectors, but it gave me no clue to do all the rerouting and rewiring to make the ATX power supplies work, mainly because it had different voltages in each pin wether the emac was on or off.

I see this project like some kind of BIG CHALLENGE, and it would be great to be able to use all the eMac Digital Modules on a Great Performing Processing Center (I'm planning on using it to render video and other calculation-intensive applications).

Any help would be appreciated,

Thanks.

kkrouse

Jan 14, 2005, 09:52 AM

Hi

As a Newbie to this discussion, I tremble at my audacity in offering input to my hero ibodnar. I have been working on this video issue as well; but first a little history. My machine was an 800 MHz eMac that my School Corp. delivered to me brand new (about a calendar year after it had been discontinued: record time!). It only had 9.2 installed on it, so I bought a copy of 10.2 OSX. I discovered later it was shipped with OSX preinstalled but the Corp. (May they slowly roast!) deleted it so as to be in accord with their standard, “No really useful stuff allowed” policy, aargh!
I decided to try the “biggie” first and was able to clock it to 1.33 on my first try. It has run with total stability ever since. I then installed a 250 GB internal hard drive and though Disk Utility hiccupped up a little gob (something like this disk cannot be read) it still formatted almost all the space. I think I ended up with about 238 GB of usable space. I installed the old 40 GB drive in a Firewire enclosure. This comes in handy when I need to boot the internal drive externally, but don’t want to drag another machine over to target it though fire wire. Next, I used the Screen Spanning Doctor app, and was able to run spanning to a 19 inch CRT. I also overclocked the video card at this point using the ATI app mentioned earlier in this thread, and upped the ram to I GB. I also hooked up a 300 GB internal hard drive mounted upside down under my desk powered by an old salvaged pc ATX power supply, also so mounted, and connected by a long round IDE Cable to the underused optical drive’s IDE channel. (I cut a notch out of the little white bottom cover plate and gave it running room by adding Apple’s eMac Swivel Base).
This was a truly awesome advance for me as a teacher. Do not ever think you are dabbling in side waters if you enjoy what you are doing. Enjoyment breeds real creation. I was able to have my classes work while viewing the CRT image projected by my(see above Corp. policy) Infocus X1 while I worked ahead of them on the eMac screen readying the next conceptual or exploratory, graphic, activity, or web diagram.
This worked so well that I decided to buy a 21.3 inch Samsung LCD flatscreen. This turned out to be a little tricky because of the limitations on eMac resolutions on the Apple end and the limitations of my presenter on the other. Using an app called Switch Res X, I am now able to release all available resolutions on the onboard ATI 7500 plus custom make my own. I was able to span my LCD at its full native 1600 by 1200 in analog mode. This works in OC mode as well as at stock video frequency settings. Unfortunately, my X1 couldn’t handle this no matter how closely I matched its optimum frequencies. The best I could do with it in the loop was in the 1200 by x range.
So I just bought a new Optima EP-751 XGA capable presenter that can handle 1600 by 1200 and am now able to put two full working applications on my spanned display so that I can slide developing concepts right into text apps without any fiddling about and still work ahead of them on my own screen. I am going to mount the presenter in my classroom ceiling now and use my old chalkboard as a big 16 by 9 ratio 20’ screen.
I would love to get digital capability next, but the prospects for this do seem dim. I tried to just hook up a VGA to DVI adapter hoping the signal was there as the OEM and desktop Mac versions of the ATI 7500 were designed for digital output, but no go! I would sure like to know what that unpopulated connector is on the MB??? No one on this thread seems to have figured out what that is yet. Could that be a technician’s diagnostic port for the video card? If so, what goes in might come out. Or might this issue be a hackable item? I am pretty sure that DVI signals can be routed through VGA pin ports. Something in between the ATI app and the Switch RES X app might release the digital signal.
Well, I have gone on long enough; maybe the moderators will give me credit per paragraphs for my posting records. Thanks again Ibodnar and all, you have truly helped out very needy kids with your work. I just wish I would have discovered this thread earlier as all I had to go on before now was Ibodnar’s Web site NFO. Thanks again.

Rod Rod

Jan 14, 2005, 04:25 PM

I have ordered 1.25GHz Mac mini in stock configuration. The soldering iron is warming up while it's being shipped (Jan 22).
:D

I still think eMac is great as a dual display box. If I only had time to sort internal CRT connection out and get it to drive external display.

Maybe you've already seen this, but just in case you haven't:

Pictures of the Mac mini's logic board (http://www.macnews.de/gallery/displayimage.php?album=16&pos=20)

edit: you might like this link (http://www.macnews.de/gallery/thumbnails.php?album=16&page=2) better.

lbodnar

Jan 15, 2005, 09:58 PM

...This was a truly awesome advance for me as a teacher. Do not ever think you are dabbling in side waters if you enjoy what you are doing. Enjoyment breeds real creation.
...
Thanks again Ibodnar and all, you have truly helped out very needy kids with your work.

Hey, kkrouse, you are my hero now! It is truly awesome what you did and I suspect you also got lots of pleasure on the way!

On a more practical note, your 238GB is in fact more than 260 billion bytes that is how HDD people count things... I have now 250GB Maxtor:

Total Capacity : 232.9 GB (250,059,350,016 Bytes)

All, bigbadmac's site (eMac 700MHz instructions) is gone but he will be back on a new frequency soon.
Maybe meanwhile I can provide a copy of his instructions starting sometime next week.

jspivack

Jan 17, 2005, 05:21 PM

I have managed to measure voltages on eMac motherboard PSU connector shown here (http://www.lbodnar.dsl.pipex.com/eMac/pics/eMac-heatsink-4.jpg).
Pinout considered to be:
08 07 06 05 04 03 02 01
16 15 14 13 12 11 10 09

Pins eMac ON eMac OFF
---- ------- --------
01 02 +20.3V +12V
03 04 +12V +12V
05 06 GND GND
07 +19V +11.5V
08..12 GND GND
13 +0.3V +8V
14 +0.3V +0.3V
15 +5V +5V
16 GND GND
1,2 and 3,4 looks like high current main power
7 ???
13, 14 - control signals to/from down converter board
15 +5V TTL logic power

Anybody willing to discuss that here or in e-mail?
Actually, I'd love to discuss that here. I've managed to get my hands on an 800Mhz emac that allegedly has a shot analog board. I'd like to pop it into a custom case, and I have a nice slient ATX power supply lying around. So i figured I'd ditch the analog board completely, use the mini-vga to get video out, and bingo! But I'd like to get confirmation of the power connector pinout. Do you have any more information - what to connect to pin 7, and confirmation of the rest of the pins?
ATX connectors:
http://www.ee.surrey.ac.uk/Workshop/advice/conns/connPSU.html

http://www.bluemax.net/techtips/ATXPowerSupplyWiring/ATXPowerSupplyWiring.htm

http://www.powerstream.com/itx-atx-pinout.htm

Thanks
Jeff

jspivack

Jan 19, 2005, 01:01 AM

lbodnar

Jan 19, 2005, 02:37 PM

Just to follow up:

lbodnar: are the voltages you mention above no-load?
does anyone out there think that pins 01, 02 and 07 will drop back to 12V under load?
none of the ATX documentation that I've found mentions such high voltages...

Jeff

Hi Jeff, voltages are in booted up state.
Don't try to match them to ATX standard (apart from +5/+12) at this stage as it will only complicate things. PSU seems to be custom-designed so the best approach is to get inop PSU and reverse engineer it (should not be difficult.)

eMac service manuals have troubleshooting procedure where they mention actual voltage on a few pins.

I use eMac as my home computer at the moment so cannot have it down.
Maybe after January 22nd :)

jspivack

Jan 20, 2005, 07:50 AM

Hi Jeff, voltages are in booted up state.
Don't try to match them to ATX standard (apart from +5/+12) at this stage as it will only complicate things. ouch. thanks for the heads-up.PSU seems to be custom-designed so the best approach is to get inop PSU and reverse engineer it (should not be difficult.)I'm a mechanical, not electrical engineer, so that's going to be tricky. it's too bad that the PSU and the CRT circuitry all so intertwined...my real goal was to try to eliminate the high-voltage CRT circuitry since I won't be using it; the assumption was that since it's on the same board as the PSU the safest and simplest thing would be to replace the whole thing with an ATX. I suppose I could still do that, if I added the proper upconverters (12V to 20V)...eMac service manuals have troubleshooting procedure where they mention actual voltage on a few pins.I've got a couple of manuals, but I didn't look that closely. I just scanned for pinout diagrams. I'll go through them more carefully.I use eMac as my home computer at the moment so cannot have it down.
Maybe after January 22nd :) placed your order yet?;)

Thanks again
Jeff

lbodnar

Jan 21, 2005, 04:59 PM

placed your order yet?;)Yes! :p

gothicspikey

Jan 22, 2005, 08:21 AM

i have a real problem, i decided to take my emac apart to have a look at the size of the jumpers and see if i was confident enough to attempt soldering, i had it open and decided to read the manual 1 more time so i put it back together, i plug it in, pressed the power button....nothing, i didn't nothing to the mb at all all i did was removed the cd drive to have alook so i don't kno what could have happened, i noticed earlier today tho, that when u plug it in, if u go close, i think the hard drives spinnin even before u press the power button, and when u unplug it it makes strange noises as it slows down :confused: can anybody help me??? thanks in advance xx

Spike

yantao

Jan 22, 2005, 11:03 AM

HI ALL . i 'M CHINESE , my English is poor.I 'M VERY GLAD TO FIND THIS WEB.

take apart it again ,to check the line of monitor connect to the computer .
If you did not connected it the power switch is not work .

I 'm trying to repair a emac, so I had to take apart the computer ,because it have in the H-direction shake.

gothicspikey

Jan 22, 2005, 03:29 PM

i checked all cables and there all in correctly, there doesn't seem to be abything out of the ordinary, tho it still won't come on, any ideas? :confused:

netjosh_granada

Jan 24, 2005, 12:03 PM

I have the next question:

In the 1st generation eMac, the logic board has TWO blind-mate connectors that go directly to the analog module assembly, whereas the 2nd and 3rd gen eMacs have only one.

I don't know if the second connector is of any use (if it is there, it must do something :confused: ), or if I can try power up the eMac directly through the main connector (the one which is common in all generations) using an "hypothetical" ATX conversion with the voltage info available in this thread.

If someone has access to a 1st gen eMac, it would be of great help if he could measure all pin voltages in both blind-mate connectors.

And another thing, I've heard somewhere that there is a document only avaliable to Apple techs which provides al the information about the blind-mate conector voltages and on the internal video out (interesting to output video without mirroring), apart from other info that would be really interesting to see :p

Thank you all...

yantao

Jan 25, 2005, 10:07 AM

i checked all cables and there all in correctly, there doesn't seem to be abything out of the ordinary, tho it still won't come on, any ideas? :confused:

I 'm repairing emac , I' m sure you are did not connect some cable.

Now follow me ,please.
1, connect the power line and swith on , listen carefully , the fan running or the hard disk running, so the power is on .if nothing happen ,that to say you computer did not connect the power.

2. open the emac ,and disconncet the power switch , use some smaller cable to conncet the red and black line.(not thick black one ), if power on , then the switch is not work well.

3, look care for, in the middle of monitor a connecter to main board, and three line , and FBT line CAP and a line at the back of the monitor near the fan connect to the mainboard .

4,check the line at the front of monitor ,

5.if all connect ,you did not power on . your computer is sure erro.

you need a professional help.

netjosh_granada

Jan 25, 2005, 01:50 PM

Today while surfing the net I have found a web page (http://www.ct-scan.com/iMacATX/) where it is performed an IMAC ATX conversion.

What is revolutionary here is that it is performed without any aftermarket solution (see Marathon Computer) and because I've thought this would be a great way to power ANY eMac motherboard WITHOUT the Analog Module.

This new idea is the following:

Before finding this web page, I thought the eMac motherboard SHOULD be powered only through the "Blind-Mate" connectors available in the logic board, and so the down converter board should make it's work of providing the necesary current to each part of the logic board (including both drives power headers). This had lead all of to the problem on HOW to measure voltages in both "Blind-Mate" connectors (only one if 2nd and 3rd generation eMacs).

NOW, the idea is to power the logic board directly through the Down Converter Board's connector, which is the path followed by the author of this web page.

Now the "bad" news that I have for this project:

The IMAC down converter board has 24 pins, all ordered and compared to its ATX counterpart in the diagram above, BUT (and this is a BIG BUT), the EMAC down converter board has 20 pins, and this is where I have problems when assigning each pin with its ATX counterpart.

Now, I'm BEGGING anyone who could have access to an eMac (better if is a 1st generation one), to measure each pin voltage in the Down Converter Board connector, because this is the only thing that stops me from using a wonderfull eMac system out of its original enclosure.

Please, this help would be appreciated and would help me in achieving my next Big Project Goal, which is the rerouting of the internal video to an external monitor (something not too difficult given the great instructions found in this web page http://www.ct-scan.com/iMacATX/).

Thank you all in advance...

guysebfan04

Jan 26, 2005, 06:08 AM

I am considering buying an eMac and just wanted some opinions from people who may own or use or have used an emac!

Compared to Apple's other desktops how are they? Would it be worth my waiting to see if a G5 model comes out soon.

I have never owned a Mac before and would greatly appreciate any advice or tips you might have!

Katherine

madmaxmedia

Jan 26, 2005, 12:07 PM

Well, most of the people here will give you positive feedback about the eMac, since we are all owners!

You should probably browse the forum for product buying advice:
http://forums.macrumors.com/forumdisplay.php?f=54

In general, the eMac is a fine machine if you don't mind the extra size and weight of the CRT monitor. It is similar to the Mac Mini, but has the advantage of 2 RAM slots and a faster hard drive (which does make a difference.)

Rumors are all over the place on a G5 eMac, but it doesn't appear to be imminent. The eMac is a fine performer as it stands-
http://www.macintouch.com/perfpack/comparison.html

Finally, there are some great deals on refurbished eMacs at Apple.com. I got one for $549 with a full warranty (which I promptly voided by swapping in a larger HD.)

lbodnar

Feb 1, 2005, 07:48 PM

Guys, I have just took apart my 1.25GHz Mac mini ... correction, make it 1.5GHz Mac mini!
You are welcome to join the new thread if you are interested.
http://forums.macrumors.com/showthread.php?t=108335

See you all there! Let's keep this one eMac/iMac - specific. I am going to go back to eMac stuff later after making mini my current home machine :)

Well, I am writing this from it now.

eryk

Feb 2, 2005, 04:53 PM

Upgraded my 1GHz eMac (2nd Gen) to a 160GB 7200rpm Maxtor drive with 8/mb cache today. It was my first time taking it apart but I didn't find it confusing. The most difficult part was removing the screws holding the EMI shield on. I almost stripped two of them trying to remove them. I think the shield was improperly aligned and someone/thing forced the screws in there anyway. I didn't have this problem anywhere else.

The rest of the removal went smoothly. I swapped the drives and placed my old drive in a firewire enclosure. Reassemble wasn't difficult. I wish I had labeled the groups of screws I made accordingly but I eventually figured it out. :D

I powered on the machine and booted the OS X install CD. It installed fine. There was something weird happened to the picture, though. The bottom half of the screen was jiggling when the hard drive was accessed. The drive was also a lot louder than the stock Hitachi. I thought setting the Automatic Acoustic Management to silent mode might stop these vibrations (???) from affecting the CRT. The only tool I could find required a boot into OS 9 so I Googled and found how to do it via OF (http://www.macosxhints.com/article.php?story=20041014005324939).

It worked great and the drive booted up as silently as the stock drive with no screen jiggling. It's really nice to have such a large drive inside the eMac now and the Hitachi in my aluminum firewire enclosure is silent as well. Perfect for backups.

Thanks for the helpful and encouraging postings here. Overclocking and upgrading the drives are a great way to lengthen the lives of these great little machines.

VAmin

Feb 5, 2005, 06:09 PM

Thanks man. Unfortunately, until someone opens one up, and pulls off that cover, we can't see what the clock chip is to see what those points control. Perhaps I can google around a bit...see if anyone has an image of the current G5 cpus/clock chips. If we have a very similar number of banks for the cpu/fsb, then it's likely to be the same.

This guy has pics and preliminary jumper settings for the G5 towers. Probably very similar to iMac G5:

http://24.13.230.40/overclock/g5.html

ruben ruben

Feb 7, 2005, 10:27 AM

I realize this is a little late, but does anyone have the pdf or a new link to bigbadmac's instructions for overclocking the 700mhz eMac. I had been visiting the site recently and it seems the webserver has changed or it has been pulled. I did not print it, and I am at somewhat of a loss without it. Thanks in advance.

I have the same problem - I need the pdf-version of bigbadmacs instructions of overclocking the original 700 MHZ eMac. Does anyone have it and is willing to share it. Or is there a new link for bigbadmacs site ?

regards from germany

lbodnar

Feb 8, 2005, 04:44 PM

netjosh_granada

Feb 8, 2005, 07:21 PM

OK, I broke loose again! Since I have moved more or less to mini, I am going to finish my plans for eMac ATI 800MHz/1GHz. I have it all in pieces on the floor and I will be tracing low voltage PSU next few days. I'll be posting notes here. Hopefully this thread will not disappear (like 700MHz instructions :()

Plans at the moment are:

1) headless emac (in a rack case or pizza box)

2) TFT eMac (replace CRT with 17" flat screen and use empty space for extra 2 HDDs.)

If you want to brainstorm this while eMac is still alive, welcome. Let's make a dent in this universe!

Hi lbodnar, I have a great mod waiting for a little info I think only you can provide.

My plan is to use a 1st generation eMac (700 Mhz - Geforce 2MX) into a new case, because the analog module died some time ago. I have found the way to power it up and to trace the internal video out to an external monitor.
I'll explain:
1) ATX Power Supply connection. Before (in the middle of this thread), you measured voltages on the BLIND-MATE connectors, because it was the "logic" place to look at. I think we were wrong, because if we see, for example, all the iMac conversions arround the web, the logic board is feed through the Down converter board connector (24 pins for iMac, 20 pins for eMac). I have been looking all around the web for this info but it is not available, and I KNOW that this is where the ATX PSU should be connected to. The voltages on the Blind-Mate connector were a mix of High current lines (which go directly to the down converter board) and video signals (which takes me to the 2nd point).

2) Internal Video Connection. If I'm right (which I don't know), the Blind Mate connector of the logic board is the place to look at when searching video signal, as it goes directly to the Analog Assembly as has enough pins to hold power lines and video signals. I think that Apple didn't complicate itself when it designed the eMac innards, and so they used the same connector as the iMacs (yes, iMacs have Blind-Mate connectors too).

So resuming, I think that if you could post info on the eMac Down Converter board connector voltages, I would be the first to test if it were possible to power an eMac logic board with an ATX PSU, and if it works we would concentrate on wiring the video though the Blind-Mate connector.

Here's a pic of the Down Converter board connector:
http://www.jmcastillo.net/emac_af.jpg

And here's a link of an iMac conversion which can help (this is where I thought about feeding the Logic board through the Down Converter Board connector):
http://www.ct-scan.com/iMacATX/

Whatever you think, say it...

lbodnar

Feb 8, 2005, 09:03 PM

netjosh_granada

Feb 9, 2005, 05:49 AM

netjosh, very quick answer before I forget...

It looks like 1G and 2G eMacs are quite different. I see where you are going - throw away downconverter board (DCB) and power it all up from ATX PSU as if DCB is the only power source.

Unfortunately in my eMac not all the vital voltages are provided by the DCB. CPU is drawing its power via DC-DC converter on the man logic board and it needs its +12V (called CPU12V) directly off 16-pin blindmate connector (which I have only one)

I'd like to get rid of DCB but it is not going to be easy ... :(

Basically the whole eMac is driven by two high current voltages - +12V that goes directly to CPU DC-DC and +20V that goes to DCB to be processed further.
There are also trickle +5V, Firewire power +15V and two feedback control signals: DCO (downconverter ON) and PRO (?)

Video cable is not on a blindmate connector as in 1G eMac but on a separate 16 pin connector.

Let's see the differences beetwen 1G and 2G eMacs:

- 1G eMac has 2 Blind-Mate connectors, each with 20 pins, while 2G has 1 BMC with 16 pins.
- 1G eMac has a 20 pin Down Converter Board connector, while 2G has a 22 pin DCB connector.
- 1G and 2G eMacs have the internal video connector on the same place but while the 1G connector is processor-side (and performing 18 pins), the 2G is facing memory-side (with ¿? pins), so I was wrong before (I have just read both apple service manuals).

It's true that both eMacs are really different, and that leaves me without any chance to use a wonderfull 1G eMac logic board until someone measures voltages on the DCB connector of a working 1G eMac (something VERY EASY and without any danger).

When powering the eMac with an ATX PSU, I thik it would be done by connecting one ATX +12V line to the BMC and measuring DCB voltages to connect directly the ATX PSU without having to search for a +20V DC-DC converter.

This is what I think. If I'm wrong, you just have to tell me...

lbodnar

Feb 9, 2005, 01:33 PM

OK, here is eMac 800/1GHz model down-converter demystified:

Pinout:
1 Return loop for 2.5v voltage sense. Connected to p.3 on the logic board
3 2.5v supply to logic board
5,7 5v supply to logic board
9,11 3.3v supply to logic board
12 enable 12v (to logic board and drives) active high (+2.5v..12v)
13 PRO voltage on this pin signals overvoltage condition on one of the outputs
14 HDD/CD on - active high - switches 5/12v to two attached power leads
15 DCO turns the whole down-converter on - active low (ground)
17,19 20V input from analog board PSU via logic board
21,23 12V supply to logic board (activated by pin 12)
2,4,6,8,10,16,18,20,22,24 GNDFeeding and care of DCB:

apply 20V to pins 17,19
ground pin 15
2,5v 3.3v and 5v are now on
apply some voltage to pin 12
12v is now on (logic board)
apply some voltage to pin 14
HDD and CD drives are starting up

What could have been easier?! :D

Main DC-DC controller chip is TPS5130 (http://www-s.ti.com/sc/ds/tps5130.pdf)

netjosh_granada

Feb 9, 2005, 02:33 PM

great job lbodnar.

You are a genius...

Now it would be great that someone would measure voltages on a 1st generation eMac so we all that have a 1st generation one (working or not) could do a great variety of mods...

I'll send the best beer I can find by Air Mail to the first who measures voltages on a 1st generation eMac.

lbodnar

Feb 10, 2005, 11:19 AM

OK, I have good news for you!

After storming the analog board for quite some hours I am basically done.
I have disabled high voltage part of it, disconnected IVAD module (the silver can) and can run it both headless and with external TFT in place of external CRT. Few things to mention:

1. IVAD silver can was tightly integrated in powerup process so some simple hacks were needed to get rid of it.

2. After full powerup the 20V and CPU12V to logic board sag to about 10V and 6V respectively. This is yet unresolved problem. Part of the PSU voltage feedback control is fed from high voltage (Vsync) circuit so I can't fix it (yet). However eMac runs perfectly on half-voltages due to the fact that DC-DC converters can pull it off until their input V approaches their output. To cut it short due to 20V sagging to 10V, internal drives get only 10V instead of 12V and cannot startup. I boot off external Firewire drive with no problems. I understand most of the projects will move away from native analog board PSU anyway so this is not a problem. In theory one good quality 12V 4..5A PSU should be enough to power both CPU and the drives.

3. Even after getting external display connected the resolutions are still those used by internal Mac screen. 1280x960 is filling up my 19" TFT in native 1280x1024 quite nicely leaving small horizontal black borders (I don't want to stretch it up.) However setting something like 800x600 locks you out since you end up with 112Hz refresh rate that monitors do not support and you will have problems getting back in. I had to create autostarting VNC server on a bootable Firewire drive and then boot off it and then get via VNC and reset the screen. I am sure this sits somewhere in OF settings or maybe in Boot ROM... I know you can use SwitchRez-like software to set any resolution but it is still nice to have monitor details read at startup.

4. By keeping Downconverter board, we can get away with just one or two main voltages and all the power control functionality is preserved: power button, sleep, wake up all work as they should.

That's it so far. eMac is quite cool to run with passive cooling as you can see!

OK, I need some rest... :D

vga4life

Feb 11, 2005, 08:30 AM

Leo, you rock!

I'm a little confused on your most recent update - are you running the LCD on the external video connector or have you tapped the internal display connector?

Now that the mini is out, the one advantage of the emac is the ability to run dual monitors. It'd be sweet to be able to use an emac logic board to drive 2 TFTs, even if only with an analog signal.

-vga4life

lbodnar

Feb 11, 2005, 11:24 AM

...are you running the LCD on the external video connector or have you tapped the internal display connector?I am using internal connector, you can see the blue VGA plug on the picture going into a cable that used to be internal video cable.

Update: I have made a simple internal eMac video <-> standard VGA converter to use until I find a proper new case for eMac, also use SwitchResX (http://www.madrau.com/html/SRX/About.html) to force native resolution 1280x1024, now image is crisp and beatiful (on par with Mac mini's DVI) and fills up the whole TFT screen. We're back in business!! Can't wait to run eMac on two 19" TFT screens side by side! :eek:

lbodnar

Feb 12, 2005, 02:00 PM

Here is mighty eMac, running off standard PC PSU and driving two 19" TFT displays at 1280x1024 each. That is 32" corner to corner!
I like the space and the price. If one could only find cheap source of eMac logic boards now...

12 Feb Update: Managed to completely separate logic and analog board! Now all that needed to run eMac headless is just a standard PC power supply. I have tied together Firewire, CPU12V and +20V voltages and feed them all off +12V. eMac runs with no problem! Obviously HDD and CD need to be powered directly off PSU (as downconverter board cannot make 12V from 12V) and Firewire voltage is slightly less the one in stock eMac but still within Firewire specs.

Now all that is required for the project like this is eMac logic board with downconverter and PC PSU. There is no need to take anything else from eMac. Both - VGA and power connectors are easy to make.

Hey, is there anybody out there reading this or I'm just blogging!?..

topgunn

Feb 12, 2005, 10:21 PM

Hey, is there anybody out there reading this or I'm just blogging!?..

I have been subscribed to this thread for over a year and still enjoy keeping up with it.

zyuzin4

Feb 12, 2005, 11:12 PM

I have been subscribed to this thread for over a year and still enjoy keeping up with it.

same here, although I don't know how it has stayed subscribed so long

vga4life

Feb 13, 2005, 09:04 AM

Now all that is required for the project like this is eMac logic board with downconverter and PC PSU. There is no need to take anything else from eMac. Both - VGA and power connectors are easy to make.

Hey, is there anybody out there reading this or I'm just blogging!?..

Reading with great interest! Can you give us more details on making the VGA and power connectors?

I'm trying to dig up details on the 3rd gen emac now without tearing apart my own (since it's my main computer) - hopefully the pinouts are the same, since I would really love to do an ATX conversion and replace the internal CRT.

-vga4life

guylan

Feb 18, 2005, 04:36 PM

I have an eMac 700 Generation 1 logic board.

I am interested in making this thing work.
I have spent nearly 4 hours of reading all of the forums I can find and looked at all of the iMac conversions that have been done and the g2 eMac conversions but allas none of those help as this board is totally different.

I have ram, HD, CD-RW, ATX case and 400w ATX p/s, and a 17" external monitor.

1) Has anyone figured out the pins for the PSU (mine has 20 pins)
2) Has anyone figured out the blind connector for the video and which one to use? (mine has 2 of them)

BTW congrats IBODNAR very nice work!

Thanks

MrFX

Feb 22, 2005, 11:32 AM

Hello!

I've a 2G eMac-Board (1.25) without the Down Converter Board. Is it possible to get the Mac running without this board?

MrFX

lbodnar

Feb 22, 2005, 03:24 PM

I've a 2G eMac-Board (1.25) without the Down Converter Board. Is it possible to get the Mac running without this board?This must be the 3rd generation eMac.

In the 2nd gen eMacs downconverter board produces +5 +12 +3.3 and +2.5V voltages. If the 3rd gen DCB is more or less the same (I assume it is) then it is possible to replace it with ATX PSU and an extra 2.5v linear regulator, I think it is pretty low current source (SDRAM ?) At least in 1st gen DCB 2.5v supply is just a simple linear regulator. Maybe just LM317 and two resistors would do. All other voltages are available as is from PC ATX PSU.

No, I don't know the pinout :D [yet!]

MrFX

Feb 22, 2005, 04:17 PM

Hallo!

OK, it's the Board with the DDR 2700 and the 3 USB 2.0 Ports. I've got the board still not, but can get it.

@lbodnar
Have you the pinout for the internal video connector (as shown in your picture)? How have you connected it to the external Display?

Bye.
MrFX

bigbadmac

Feb 22, 2005, 05:52 PM

Here's the thread for 700 MHz eMacs...

700 MHz eMac (http://forums.macrumors.com/showthread.php?t=111922)

I'll post replies to that thread for any 700 MHz questions.

lbodnar

Feb 23, 2005, 08:36 PM

Have you the pinout for the internal video connector (as shown in your picture)? How have you connected it to the external Display?Yes, I have connected my gen 2 eMac but since gen 1 has a different internal video pinout I would assume gen 3 eMac might be different too.

MrFX

Feb 24, 2005, 06:39 AM

Hi,

but someone said, that the Gen 3 Board can used as a replacement for the Gen 2 Board... ok, i'm still waiting for the photos from this board and then we will see...

MrFX

MrFX

Feb 28, 2005, 01:36 AM

madmaxmedia

Feb 28, 2005, 01:53 AM

Hello again,

i have now some photos from the Gen 3 Board, it looks like a Gen 2.

I think, i will get the whole Digital Assembly as on the picture, so the Down Converter is included.

@lbodnar
Can you post the internal video pinout from the Gen 2 Board and what modifications you made in the OF to get it work?

Best wishes,
MrFX

Hi MrFX,

Can you take some detailed pics of the motherboard? I have a Gen 3 (I think, is that the current line?) that I want to overclock. However, it seems there is some confusion over where the jumpers are to do this.

My eMac is a 1 GHz edu model, so I would really love to take it to 1.4 or so...

Thanks,
Steve

MrFX

Feb 28, 2005, 02:11 AM

Hi,

sorry, i have the board not yet...

Gen 3 board have DDR-Ram and USB 2.0

MrFX

madmaxmedia

Feb 28, 2005, 02:25 AM

Hi,

sorry, i have the board not yet...

Gen 3 board have DDR-Ram and USB 2.0

MrFX

Yeah, that's mine!

If you get the chance whenever, that would be wonderful!! I know topgunn also wants to overclock his Gen 3, but couldn't find the jumpers.

My family uses this eMac a lot, so I'm not able to disassemble and leave it unusable for too long.

lbodnar

Feb 28, 2005, 08:08 PM

Can you post the internal video pinout from the Gen 2 Board and what modifications you made in the OF to get it work?I have dumped all the information and photos on http://www.lbodnar.dsl.pipex.com/eServer/

I'll get around sorting it out someday but for the moment it should be enough to get you started!

Happy tinkering!

punkrockscks

Mar 1, 2005, 01:06 AM

i just got done overclocking my 1ghz gen 2 emac to 1.4 ghz.. everything is going well, just it took me all evening and almost had a heart attack a couple of times....
i just kinda read a posting about how to dissassemble the emac, which im my opinion was the hardest part, then followed the instructions in the links above. one word of advice, don't mess with putting the same resistors back on, just use some soder to make the "bridge". much easier than the resistors. i knew they were small, but god, they're really tiny.

best of luck to anyone else trying it out!

MrFX

Mar 1, 2005, 01:19 AM

Hello!

@lbodnar

Thanks alot for the fantastic informations... i will try it ASAP.

Bye.
MrFX

MrFX

Mar 1, 2005, 01:13 PM

Hello again!

Does anyone have the Service Manual for the newest eMac-Series (not the one called emac_ati_graphics.pdf)?

I would compare the part numbers with the board i would like to buy.

Bye.
MrFX

MrFX

Mar 4, 2005, 07:32 AM

Hello!

I've received the board yesterday and will take some hi-res photos next days...

So long.
MrFX

madmaxmedia

Mar 4, 2005, 11:51 AM

Hello!

I've received the board yesterday and will take some hi-res photos next days...

So long.
MrFX

Thanks so much!

BTW- Since you will have an open board, will you be overlocking it too?

-Steve

guylan

Mar 6, 2005, 10:11 PM

Ok I bought a 700mhz mac off of eBay to just get these voltages!!!

Blindmate nearest External Connections:

*pin one is in the upper left corner as you have the RAM sockets facing you and the CPU to the right side!!! Pin two is below pin one. => top row is odds and bottem row is evens.

1 Red Mic (5v)
2 White Mic (Sig)
3 Mic (GND)
4 Mic (GND)
5 Power Light (+)
6 Power Light (GND)
7-10 NC
11 FAN (Speed Sense)
12 NC
13 Left Speaker (-)
14 NC
15 Left Speaker (+)
16 NC
17 Right Speaker (-)
18 FAN (GND)
19 Right Speaker (+)
20 FAN (12v)

Blindmate nearest CPU eMac OFF with Power plugged-in.

*pin one is in the upper left corner as you have the RAM sockets facing you and the CPU to the right side!!! Pin two is below pin one. => top row is oddsand bottem row is evens.

1 12v
2 -0.14v
3 7.3v
4 -0.14v
5 7.3v
6 -0.14v
7 GND
8 GND
9 13.9v
10 GND
11 5v
12 GND
13 GND
14 -0.14v
15 GND
16 -0.14v
17 GND
18 -0.14v
19 11v
10 -0.14v

Down Converter w/eMac powered ON

*Pin out is ACTUAL!
1 20v
2 GND
3 20v
4 GND
5 0.03v
6 0.74v
7 3.3v
8 GND
9 3.3v
10 GND
11 2.5v
12 GND
13 2.5v
14 GND
15 5v
16 GND
17 5v
18 GND
19 5v
20 GND

* All of these voltages were observed with a digital multimeter and were checked 3 times sequentially.

lbodnar

Mar 7, 2005, 04:41 AM

Ok I bought a 700mhz mac off of eBay to just get these voltages!!!That is terrific! Were power connector voltages measured with logic board detached?

Will you be able to sample few voltages on a logic board with the power on?

I understand it is difficult to get to blindmate connector when eMac is on without fully taking it apart. But I will trace connections to the bottom of the board that is reachable in normal operation.

I hope solutions is near!

MrFX

Mar 7, 2005, 04:54 AM

Hello again!

Leo, have you ever measured the current, which takes the board on 12 and 20 V (with the original PSU)? If not, i will try it today in the evening and measure it.

I want to know this for looking for a little switching supply... i will not use a big ATX... :D

Bye.
MrFX

lbodnar

Mar 7, 2005, 06:12 AM

have you ever measured the current, which takes the board on 12 and 20 V (with the original PSU)?I was going to, but got distracted...

CPU 12V should be about 2..2.5A at full CPU load (based on datasheet info) and 20V power around 2A (drives included). All together I guess 100W PSU should be enough.

Are you planning to replace 20V with 12V? 20V is downconverted to 12, 5, 3.3 and 2.5V so if you power drives straight off PSU then 20V can be reduced to 12V that makes very friendly power system with just 12/5v needed. This one (http://www.overclock.co.uk/customer/product.php?productid=17252) is 250W but a nice form-factor.

Just remember that 2A on 20V requirement will become 3A on 12V because downconverter board is a switched PSU. And make sure you look at currents too as most PSUs are not very strong in 12V department. This is why it is beneficial to power drives straight off PSU, not via downconverter.

Even better, I would supply only 5V to CPU12V because it is downconverted on the logic board to 1.55V anyway and on an average PC power supply 5V power has much more current capacity (isn't it on that dedicated 4-pin CPU power connector that was introduced for Pentium 4 ATX CPUs?) I shall try it and report back!

Please post your measurements!

guylan

Mar 7, 2005, 10:02 AM

That is terrific! Were power connector voltages measured with logic board detached?

Will you be able to sample few voltages on a logic board with the power on

Yes the Blind-Mate power measurements were taken with the logic board detached. I was hoping that with those voltages we could use the info you got on your Gen2 to figure out what was to be connected to 12v and 5v but that -0.14v has got me rather confused. Although the Down Converter shows promise. I think I should be able to provide the 3.3v, 5v and 12v to the Down Converter socket and the board should power right up.

As far as getting measurements with the logic board attached....hummmm....let me put it this way....I have a pair of pliers and an achy tooth and no novacane. The only way it seems that I will be able to get any readings is if I take out the CRT and get teh voltages from the back side of the blind-mate.

lbodnar

Mar 7, 2005, 11:05 AM

I was hoping that with those voltages we could use the info you got on your Gen2 to figure out what was to be connected to 12v and 5v but that -0.14v has got me rather confused. Although the Down Converter shows promise. I think I should be able to provide the 3.3v, 5v and 12v to the Down Converter socket and the board should power right up.I do have Gen1 700MHz board with downconverter that netjosh_granada kindly sent me for testing. I have fully reverse-engineered the downconverter (don't forget 2.5v) but had no success powering the whole eMac up.

MrFX

Mar 7, 2005, 11:40 AM

Hello guys,

the Gen 3 board is running... just still with a b/w video on the internal, maybe it's just a missing wire or so... will look for it in the evening. The board takes at the 12 V line (without drives) 3.12 Ampere.

Now i'm installing X.3... :D

Not bad for 180 Euros.

So long.
MrFX

guylan

Mar 7, 2005, 12:13 PM

I do have Gen1 700MHz board with downconverter that netjosh_granada kindly sent me for testing. I have fully reverse-engineered the downconverter (don't forget 2.5v) but had no success powering the whole eMac up.

Ok here is a tidbit...

yesterday when I put the eMac back together, to install some software,(I only have this machine for another day because it is going to be installed in a customer's business) I could not get it to power back up...upon further inspection of the connectors I found that I neglected to plug in the Video connector. (While the machine was plugged in I could hear a faint whine but when I would push the power button it would go away.) after plugging the video connector back in, the machine works fine and I have been configuring it for install.

I am wondering if the internal video connector has some sort of circuitry that is required to power up the logic board.

vga4life

Mar 7, 2005, 12:51 PM

the Gen 3 board is running... just still with a b/w video on the internal, maybe it's just a missing wire or so... will look for it in the evening. The board takes at the 12 V line (without drives) 3.12 Ampere.

To be clear, you mean you have a 1.25GHz USB2 emac logic board (with DCB?) running bare?

Are you using the same adapter pinouts as leo posted for the 2nd gen emac?

-vga4life

lbodnar

Mar 7, 2005, 02:13 PM

I am wondering if the internal video connector has some sort of circuitry that is required to power up the logic board.On Gen2 board it works that way...

Everything is warmed up by trickle 5V and standby 12V.
Power On button push sensed by PMU controller on logic board.
PMU sends a message to the microcontroller on IVAD board (inside silver can) via two I2C wires on a video connector. They are not VGA DDC data link and also used to control CRT brightness, geometry, etc.
IVAD microcontroller sends PWRON signal (high) to analog board.
Analog board inverts it and makes sure overvoltage signal (PRO) is OK (low)
Inverted (low) power on signal (DPO) is sent to logic board via blindmate connector.
This gets directly through to downconverter and activates it.
the rest of the magic happens :)
As you can see it involves nearly all available resources to simply power the thing on!
My solution is to just permanently ground DPO on the blindmate connector.

Same logic and signals apply to Gen1 board too.

lbodnar

Mar 7, 2005, 02:31 PM

Generation1 eMac downconverter board (DCB) pinout:
1,3 20V from analog board power supply. This is INPUT to DCB.
2 Gnd for 20V
4 Gnd sense for 20V
5 PRO - overvoltage signal (active high) output.
6 DCO - turns DCB on (active low) input
7,9 +3.3V
11 +2.5v
13 +2.5v sense
15,17,19 +5v
8,10,12,14,16,18,20 Gnd
If you want to replace DCB altogether, connect all Gnd together and provide permanent 5, 3.3 and 2.5v to logic board. 2.5v is pretty low current (DRAM) so linear regulator off 5 or 3.3v will do.

netjosh_granada

Mar 7, 2005, 02:32 PM

On Gen2 board it works that way...

Everything is warmed up by trickle 5V and standby 12V.
Power On button push sensed by PMU controller on logic board.
It sends message to a microcontroller on IVAD board (silver can) via two I2C wires on video connector. They are not VGA DDE data link and also used to control CRT brightness, geometry, etc.
IVAD microcontroller sends PWRON signal (high) to analog board.
Analog board inverts it and makes sure overvoltage signal (PRO) is OK (low)
Inverted (low) power on signal (DPO) is sent to logic board via blindmate connector.
It gets directly to downconverter and activates it.
the rest of the magic happens :)
As you can see it involves everything in simply powering the thing on!
My solution is to just permanently ground DPO on the blindmate connector.

Same logic and signals apply to Gen1 board too.

Do you mean that without IVAD, emac won't power up?
What a strange design Apple did with this computer...

lbodnar

Mar 7, 2005, 02:37 PM

Do you mean that without IVAD, emac won't power up?It will if you forcefully switch downconverter board on (by grounding DCO signal on blindmate connector.)

MrFX

Mar 7, 2005, 04:04 PM

Hello all,

yes, i'm running the 1.25 GHz eMac (Generation 3, USB 2.0, DDR-RAM) headless... only with the downconverter and the pinouts posted by Leo.

This posting i'm writing with it :D

But there's still a problem with the monitors: they're not recogniced, both, internal and external. The internal screen shows me 640x480, the external 1024x786, no other resolutions available. I've tested SwitchResX, but no change. There is also no button "detect displays (or whatever it's called in english)"... OK, i will try a little bit more...

Leo, do you have a logic analyzer? Can you log the I2C-communication with the IVAD-module? Maybe, there are some changes in the Gen 3 board... or we can simulate the communication...

Bye.
MrFX

guylan

Mar 7, 2005, 04:07 PM

Ok here is the Blind-Mate connector updated

Pin one is in the upper lefthand corner with the polarization tab on the top.

PIN mac off mac on
1 12v 17.5v
2 -0.14v GND
3 7.3v 12v
4 -0.14v GND
5 7.3v 12v
6 -0.14v GND
7 0v 12v
8 GND GND
9 13.9v 4.92v
10 Chassis GND Chassis GND
11 5.0v 0.72v
12 Chassis GND Chassis GND
13 0v 0.04v
14 Chassis GND Chassis GND
15 0v 10.8v
16 -0.14v GND
17 0v 10.8v
18 -0.14v GND
19 11v 18.13v
20 -0.14v GND

*there seems to be 2 different grounds at work here Common Ground and Chassis Ground.

** I am beating myself silly for not checking the connector with the mac off while the crt was removed....this may throw off all the off state readings.

lbodnar

Mar 7, 2005, 04:17 PM

1. yes, i'm running the 1.25 GHz eMac (Generation 3, USB 2.0, DDR-RAM) headless... only with the downconverter and the pinouts posted by Leo.

2. But there's still a problem with the monitors: they're not recognised, both, internal and external. The internal screen shows me 640x480, the external 1024x786, no other resolutions available. I've tested SwitchResX, but no change. There is also no button "detect displays (or whatever it's called in english)"... OK, i will try a little bit more...

3. Leo, do you have a logic analyser? Can you log the I2C-communication with the IVAD-module? Maybe, there are some changes in the Gen 3 board... or we can simulate the communication...1. I was going to say that Gen2 and Gen3 boards look absolutely identical near the area around blindmate connector.

2. You have to create custom resolution in SwitchResX and then restart. "Detect displays" read info off the DDC chip. I had no luck with internal display... But forcing resolution works for me!

3. I was trying to avoid that! I have a scope and can probably build PIC16F84 project to talk to eMac but there must be an easier way!! :D

lbodnar

Mar 7, 2005, 04:39 PM

Ok here is the Blind-Mate connector updated

Pin one is in the upper lefthand corner with the polarization tab on the top.
PIN mac off mac on
1 12v 17.5v
2 -0.14v GND
3 7.3v 12v
4 -0.14v GND
5 7.3v 12v
6 -0.14v GND
7 0v 12v
8 GND GND
9 13.9v 4.92v
10 Chassis GND Chassis GND
11 5.0v 0.72v
12 Chassis GND Chassis GND
13 0v 0.04v
14 Chassis GND Chassis GND
15 0v 10.8v
16 -0.14v GND
17 0v 10.8v
18 -0.14v GND
19 11v 18.13v
20 -0.14v GNDThis is my version:
1 supply voltage to DCB - around 20V - wired directly to DCB pins 1,3
3,5 CPU downconverter voltage (12V)
7 DCB overvoltage signal - should be around zero - - wired directly to DCB pin 5
9 DCB on - grounded when eMac is on - wired directly to DCB pin 6
13 +12V to drives pigtails (via MOSFET switch on logic board)
19 Firewire power (around 18V)

Looks like we have lost sync somewhere... Hey! You have on voltages upside down!!
My problem is pins 11, 15 and 17

Looks like pin 11 is trickle 5V

MrFX

Mar 7, 2005, 04:59 PM

OK, now it works... it's recogniced as eMac in the "Displays..."

I think, i will put a heatsink on the Intrapid... it's getting so hot. And in the final case a slow rotating fan...

I've shot the photo below to demonstrate, that it is working (ok, nothing to see...). Will take some more photos tomorrow.

Now i'm looking forward for a little PSU and some other accessiores... :D

So long and sleep well.

MrFX

lbodnar

Mar 7, 2005, 05:03 PM

I've shot the photo below to demonstrate, that it is working.
Now i'm looking forward for a little PSU and some other accessiores... :DHave look at these:http://www.achme.com.tw/products_1.php?cid=2&cgid=5&gid=34
They are used in Shuttle PCs.

guylan

Mar 7, 2005, 05:49 PM

This is my version:
1 supply voltage to DCB - around 20V - wired directly to DCB pins 1,3
3,5 CPU downconverter voltage (12V)
7 DCB overvoltage signal - should be around zero - - wired directly to DCB pin 5
9 DCB on - grounded when eMac is on - wired directly to DCB pin 6
13 +12V to drives pigtails (via MOSFET switch on logic board)
19 Firewire power (around 18V)

Looks like we have lost sync somewhere... Hey! You have on voltages upside down!!
My problem is pins 11, 15 and 17

Looks like pin 11 is trickle 5V

You are correct I did not see the pin 1 identifier....so that means that pin 1 is actually pin2 and pin 2 is acutally pin 1 etc. This goes for all of the Blindmate connector pinouts I have published to date...Looks like I will reformat them and repost them in the next hour! :)

madmaxmedia

Mar 7, 2005, 06:57 PM

Have look at these:http://www.achme.com.tw/products_1.php?cid=2&cgid=5&gid=34
They are used in Shuttle PCs.

Hi Leo,

Do you think you would be able to identify the jumpers for overclocking the G3 eMac, if MrFX were to post a higher resolution photo of the motherboard?

Thanks,
Steve

lbodnar

Mar 7, 2005, 06:57 PM

OK, very quick update for tonight.
I am finally running 700MHz bare (headless) Off the +12/+5V ATX PSU. Details tomorrow. Big thanks to guylan for live voltage measurements!

guylan

Mar 8, 2005, 12:53 AM

OK, very quick update for tonight.
I am finally running 700MHz bare (headless) Off the +12/+5V ATX PSU. Details tomorrow. Big thanks to guylan for live voltage measurements!

ok here are the updated Blind-Mate pin outs with the proper polarizations...

Blind-mate nearest CPU

PIN, OFF, ON
1, 12.14v, 18.43v
3, 7.3v, 11v
5, 7.3v, 11v
7, 0, 0.4v
9, 13.89v, 0.71v
11, 5v, 5v
13, 0.115v, 12v
15, 0.115v, 12v
17, 0.115v, 12v
19, 11.13v, 17.41v
pins 2,4,6,8,10,12,14,16,18, and 20 were all GND

Blind-mate nearest External Connections
1 Mic (+)
2 Mic Signal
3 Mic GND
4 Mic GND
5 Light (+)
6 Light (-)
11 Fan Sense (RPM)
13 Right Speaker (+)
15 Right Speaker (-)
17 Left Speaker (-)
18 Fan GND
19 Left Speaker (+)
20 Fan 12v
Pins 7,8,9,10,12,14, and 16 had no connections
* notice that pins 15 and 17 were the (-) for the speakers this would support comon ground.

lbodnar

Mar 8, 2005, 04:00 AM

Do you think you would be able to identify the jumpers for overclocking the G3 eMac, if MrFX were to post a higher resolution photo of the motherboard?Yes, of course! I know what to look for, I just can't see it from existing photos. I need an area around connector J11.

netjosh_granada

Mar 8, 2005, 05:10 AM

OK, very quick update for tonight.
I am finally running 700MHz bare (headless) Off the +12/+5V ATX PSU. Details tomorrow. Big thanks to guylan for live voltage measurements!

You've done a great job lbodnar. I'm already planning a great case mod for the Headless eMac's around here.

If someone has any ideas, just tell me and I'll try making it...

lbodnar

Mar 8, 2005, 05:17 AM

I really like this very well written article on PC's power supplies - http://www.quepublishing.com/articles/article.asp?p=31105&seqNum=4

The guy even remembers which pin on ISA bus got -5v on it! Impressed! :cool:

By the way can anybody quote definite Firewire standard on cable power? I have seen anything from 8v to 38v and even ridiculous quotes like 1.5A at 40V (that's 60w of power!) Macs traditionally supply around 15v..18v on their Firewire cable but I try to get lower to something like 11V by using only 12v PSU voltage. Portable drives and iSight are OK with that but I really want to see a standard figures...

jspivack

Mar 8, 2005, 05:31 AM

Leo, Guylan

This is great. Let me say I've been following this thread with bated breath for about 2 months, since a friend "gave" me his dead Gen1 700Mhz (he's had the analog board replaced 3 times, and he's pretty sure it's dead again). Until recently, most of the experimentation has been with Gen2 and Gen3 boards. I'm super-stoked to see some action with a Gen1 board.

So, let me see if I've got this straight...if I follow what Leo posted in comment #356 ("Generation1 eMac downconverter board (DCB) pinout:..."), then i should be able to boot my Gen1board
1) without DCB
2) and without analog board
3) and without the IVAD?

I would also have to ground pin 6 (DCO) on the DCB and power the HDD and CD-ROM separately. right?

OK, very quick update for tonight.
I am finally running 700MHz bare (headless) Off the +12/+5V ATX PSU. Details tomorrow. Big thanks to guylan for live voltage measurements!

Leo: here you seem to be running *with* the DCB. Have you (or Guylan) tried without it?

thanks

Jeff Spivack
Nantes, France

lbodnar

Mar 8, 2005, 09:13 AM

So, let me see if I've got this straight...if I follow what Leo posted in comment #356 ("Generation1 eMac downconverter board (DCB) pinout:..."), then i should be able to boot my Gen1board
1) without DCB
2) and without analog board
3) and without the IVAD?
I would also have to ground pin 6 (DCO) on the DCB and power the HDD and CD-ROM separately. right?Jeff, yes you should be able to, but you need to get 2.5v power from somewhere. I am not sure what does it power up but it is rather low current supply. I will try to experiment with some really cheap tricks like dropping 0.7-0.8v off 3.3v via a power diode or if not then build a quick LM317-based regulator.

You don't need pin 6 if you don't have DCB as it is an input to DCB to switch it on.

MrFX

Mar 8, 2005, 12:38 PM

Hi all...

@Leo: i've uploaded a hi-res photo from the area around J11, tif-format, you can get it here. (http://www.mrfx.de/files/eMac/eMac_gen3_J11.rar)

Now i have to clean my reallife desktop and take some more photos from the "new" eMac.

So long,
MrFX

lbodnar

Mar 8, 2005, 04:43 PM

This is the bare minimum necessary to power a Generation 1 eMac (GeForce graphics, 700/800MHz) on:

Blind mate connector J4504
pin 1 is has ^ mark on the board, pins numbered
2 .. .. .. 20
1 .. .. .. 19
^

1,3,5,13,15,17,19 +12v (needs 4-5A)
11 +5v (trickle/standby or normal)
7 leave open
2,4,6,8,9,10,12,14,16,18,20 Gnd

Video connector J2701
pin 1 is has ^ mark on the board, pins numbered
2 .. .. .. 18
1 .. .. .. 17
^
corresponding VGA connector pins are in (brackets)

3 B Video (3)
5 G Video (2)
7 R Video (1)
4 B Gnd (8)
6 G Gnd (7)
8 R Gnd (6)
11 V sync (14)
13 H sync (13)
1,4,6,8,9,14,15 Gnd (5,10)

DDC signals (SCK, SDA) are still pending but eMac powers on and works without them just fine.

MrFX

Mar 8, 2005, 04:46 PM

Hello!

I've take some photos... hope, that you all can see, what you want.

Best wishes,
MrFX

MrFX

Mar 8, 2005, 04:47 PM

Some more...

lbodnar

Mar 8, 2005, 08:11 PM

Do you think you would be able to identify the jumpers for overclocking the G3 eMac, if MrFX were to post a higher resolution photo of the motherboard?Steve, I think I have found one out of five:

R270

If the bottom pad of R275 is connected to the ground then R275 is the second one. It would help if somebody could measure few resistor values there. Anyone?

lbodnar

Mar 9, 2005, 05:22 PM

I have spent some time on it now and the only visible consumer of +2.5v supply that comes off downconverter is two Video RAM chips from Hynix (http://www.hynix.com/datasheet/pdf/dram/HY5DU283222F(Rev.1.2).pdf).

I want to get rid of DCB altogether so I was going to do it cheap and nasty by getting 2.5v from 3.3v via an inline diode do drop 0.7-0.8v however I am now starting from making a proper voltage regulator on LM317 (http://www.national.com/ds/LM/LM117.pdf) and a couple of resistors (think 2.5v output 7805). Input voltage should be 5v, as 3.3v indicated on the picture is too low for 2.5v output.

Metal mounting tab on LM317 is connected to its output (2.5v) so the heatsink (if used without mica isolation) should not be in electrical contact with metal case or any other obect connected to system Gnd.

Do you guys think average project builder will be OK with that?

madmaxmedia

Mar 9, 2005, 05:34 PM

Thanks Leo!

So does it look like the various jumpers are scattered on the board, rather than aligned in a row?

How are you able to figure it out?

Thanks, Steve

Steve, I think I have found one out of five:

R270

If the bottom pad of R275 is connected to the ground then R275 is the second one. It would help if somebody could measure few resistor values there. Anyone?

lbodnar

Mar 9, 2005, 06:27 PM

So does it look like the various jumpers are scattered on the board, rather than aligned in a row?

How are you able to figure it out?My thinking was the along the following lines...
Apple uses connector to either monitor or control CPU PLL multiplier. It is J500 (http://www.lbodnar.dsl.pipex.com/eMac/eMac-jumpers-closeup.jpg) on Gen1 and Gen2 eMacs and J11 on Gen3.
You can see that each of J500 pins 1 to 5 is mapped to one of configuration resistors.
If I would be Apple I'd carry over the pinout of the connector to Gen3 intact.
So we assume top 5 pins of J11 should end up on a configuration resistor pads.
Now we can see that pins 2 and 4 have traces leading to blocks of four resistors each. At some point in time Apple obviously was going to implement live switching of PLL multiplier using transistors Q11, Q12 on Gen3 or Q1501, Q1502 on Gen2 but left that idea out together with associated extra two resistors per each PLL_CFG bit.

So we end up with at least two (one pull-up to +3.3v and one 0 ohm "jumper") or four (two extra missing ones from legacy switching circuit) per each bit.

1.25GHz CPU on 167MHz bus should have a pattern on J11 like

+< pin 1 J11
+< pin 2
+< pin 3
-< pin 4
+< pin 5

where "+" means jumper installed and should measure 0 ohms to Gnd with a ohmmeter.

Now compare pins 2 and 4 and their associated resistor blocks - indeed we have R270 present and R275 missing.

That's it so far...

MrFX

Mar 10, 2005, 01:11 AM

Hi again,

i will measure the values today. Leo, which should i take?

So long.
MrFX

jspivack

Mar 10, 2005, 02:45 AM

I am now starting from making a proper voltage regulator on LM317 (http://www.national.com/ds/LM/LM117.pdf) and a couple of resistors (think 7805 for 2.5v output).

Do you guys think average project builder will be OK with that?

as an "average project builder", I have to say yes. although I don't have chips like that floating around my house, after a couple minutes of surfing I see that I can get them both at my local shop and online at Radiospares. Piece of cake. What sort of load do you anticipate? I see that it comes in at least 0.1A and 1.5A versions...0.1A would sound like enough to me for a couple of RAM chips, but I'm a Mech. Eng., not an Elec. Eng. ...

lbodnar

Mar 10, 2005, 12:32 PM

Piece of cake. What sort of load do you anticipate? I see that it comes in at least 0.1A and 1.5A versions...0.1A would sound like enough to me for a couple of RAM chips, but I'm a Mech. Eng., not an Elec. Eng. ...I will use 1.5A version of LM317 or LM317A in TO-220 case (the one with a metal tab and a hole on top) it is easier to work with and might not even need a breadboard to put on.

Datasheet says two chips can draw up to a maximum of 0.9A when in continuous burst mode whatever it is. If we get our power off +5v (3.3v is too low for 2.5v output using LM317) then at 0.9A the dissipated power is about 2W and with 50C/W thermal resistance of TO-220 case it might get quite a bit hot (120C!). So it looks like some simple heatsink will be needed.

lbodnar

Mar 10, 2005, 12:39 PM

i will measure the values today. Leo, which should i take?Hi MrFX, I can definitely say R270 and R275 are two of the "jumper" resistors.

To find the rest we need to find everything that is connected directly (0 ohm) to J11 pins 1,3 and 5 and to pin 2. This is a lot of probing but without this I am stuck... I also suspect that pins 1,2,3 and 5 are all connected together :(

MrFX, is there a chance to get the same excellent quality picture of the are on the reverse of J11. I just seem to be totally missing 12 resistors! By the way rar file was nearly the same size as tiff so if you can, try to save it as jpeg. We'll get it in the end.

Leo

MrFX

Mar 10, 2005, 05:03 PM

Hello Leo,

i will try this, but tomorrow...

I've packed the picture, because some browsers display tif-images instead of download... but i can try the reverse side in jpeg... it was a tif, because i've take it in raw-mode... so there was no convert necessary.

May the force be with you...
MrFX

lbodnar

Mar 10, 2005, 05:48 PM

Yes, yes, Yes!

We can throw downconverter board away. eMac will run without it!

I have temporarily tapped in power by soldering directly to the reverse side of DCB connector on the logic board and it powers up and works! My impromptu 5v->2.5v converter (see post number 379 above) gets pretty hot so I might use a better heatsink in the final version but schematic will stay the same (I have used LM317T - can't remember how it is different from LM317A or LM317, was it Vout precision?)

I supply +12v, 5v, 3.3v off a standard 120W ATX power supply.

That's basically it! eMac headless is born. Now where one can purchase bare eMac logic boards for nothing?

netjosh_granada

Mar 11, 2005, 03:09 PM

hi all again.

I'm already planning a wonderfull case for this eMac project, but I'm planning to make it fit on a standart ATX case too.

I have a question that only 1st gen eMac owners can answer (hopefully lbodnar has mine):

¿Could it be possible to raise the bus speed from 100 Mhz to 133 Mhz or even more?

I think that if it's possible to change CPU multiplier through PLL resistors, there has to be another set of resistors around the logic board to increase bus frequency without risking the CPU (i.e. 700 Mhz = 7 x 100 Mhz would be 933 Mhz = 7 x 133 Mhz --> at first should try 666 Mhz = 5 x 133 Mhz, after that... 933 Mhz or 1066 Mhz would be perfect ;-) )

I know I should need brand new memory on a 133 Mhz bus, but as I only have 128 Mb PC100 this is not a problem.

If anybody has any ideas on how it could be done, let us know...

jm2005

Mar 11, 2005, 05:27 PM

Hey Ibodnar. Great Job. Do you think I can upgrade my Powermac g4 400mhz-1.5 ghz. Am I pushing my luck here?

Jm 2005

guylan

Mar 14, 2005, 04:40 PM

lbodnar

Mar 15, 2005, 07:41 AM

Ok one question about the 2.5v(sense) is this also required to be connected?It is connected to 2.5v line on the ligic board and is used to feed 2.5v back to the DCB for voltage regulation. Just use it as a second 2.5v wire. It can be fed back into LM317 regulator to get better quality 2.5v if this becomes necessary.

lbodnar

Mar 16, 2005, 06:41 PM

Altering CPU Vcore voltage

I never found time to play with it but if someone wishes to try to increase CPU Vcore voltage to achieve higher clock speeds or decrease it to reduce generated heat, here is the information required:

Voltage controller datasheet - http://www.onsemi.com/pub/Collateral/NCP5322A-D.PDF
Controller chip is located on the front-facing edge of the board to the left of Airport connector on the bottom (CD drive) side.
Refer to page 5 for possible settings in the range of 1.1v - 1.85v to the accuracy of 0.025v.
Configuration resistors on the logic board as pictured below are in the order...
Vid0 Vid1 Vid2 Vid3 Vid4 (datasheet table is in the reverse order - Vid4 .. Vid0)
Resistor present = 0, missing = 1
Attached picture for Gen2 shows default setting of Vcore = 1.55v (hirez (http://www.lbodnar.dsl.pipex.com/eServer/L-IMG_0723.JPG))

lbodnar

Mar 16, 2005, 06:54 PM

Altering CPU Vcore voltage

Generation 1 (GeForce graphics) eMacs use different voltage chip:
http://www.semtech.com/pdf/sc2422b.pdf (1.1v - 1.85v range)
Defult voltage is Vcore = 1.75v

rmanger

Mar 17, 2005, 01:34 AM

Hi everyone!

I've been lurking on these forums for some time itching to overclock my Gen3 eMac. I hope that MrFX submits those pics soon, because I'm starting to reach my limit...

lbodnar, will increasing the CPU core voltage increase CPU performance? Or does this give only more potential performance?

lbodnar

Mar 17, 2005, 04:27 AM

I've been lurking on these forums for some time itching to overclock my Gen3 eMac. I hope that MrFX submits those pics soon, because I'm starting to reach my limit...Apparently not everybody knows that there is an "education" Generation 3 eMac with 1GHz processor, basically underclocked Gen3 1.25GHz eMac. Tim and I have managed to overclock it to 1.33GHz by shorting pads on J11 connector. Unfortunately it is not going to work with stock 1.25GHz model because to overclock it one needs to remove the configuration resistors which needs finding them first...will increasing the CPU core voltage increase CPU performance? Or does this give only more potential performance?Yes, increasing the supply voltage makes semiconductor's switching time shorter potentially giving the chance to operate at higher frequency. One still needs to increase clock frequency though! I can't remember exact formula but Freescale hints in 7447 datasheet that 10% Vcore voltage drop causes 20% maximum frequency drop ("derating"). It must be then that MaxFreq ~ Vcore^2. It obviously works both ways so upping Vcore by 10% you can potentially squeeze 20% more speed. Remember though that the CPU will generate extra 20% heat due to voltage increase and 20% more due to clock increase.
Temperature ~ Power ~ Vcore^2 * ClockFreq

MrFX

Mar 17, 2005, 07:25 AM

Sorry for the delay... i was busy the last days... hope to take the picture today...

So long.
MrFX

lbodnar

Mar 17, 2005, 02:38 PM

MrFX

Mar 17, 2005, 03:40 PM

Hello Leo,

you can download the backside-picture from J11 of Gen3 eMac board here (http://www.mrfx.de/files/eMac/eMac_gen3_J11_backside.jpg).

So long,
MrFX

lbodnar

Mar 17, 2005, 04:24 PM

you can download the backside-picture from J11 of Gen3 eMac board here (http://www.mrfx.de/files/eMac/eMac_gen3_J11_backside.jpg)Great! Here they are then:

1.25 1.33 1.42 1.50 1.58 1.67 1.75GHz
R658 (reverse side) + - + + + - -
R270 (J11 side) + - - - - + +
R673 (reverse side) + + - - - - +
R275 (J11 side) - + + - - + +
R689 (reverse side) + + + - + - -
As usual, "+" means either resistor or solder bridge is present and "-" is an open contact or removed resistor.

Just to let you know, Open Firmware might not correctly show 1.58GHz speed (displayed as 750MHz) because no Mac yet runs at that speed. This issue is the same on Mac mini - it has the same CPU and very similar architecture. It is purely indication issue and the solution can be found here (http://macminiforums.com/forums/showpost.php?p=2205&postcount=107)

lbodnar

Mar 17, 2005, 05:10 PM

Hey Ibodnar. Great Job. Do you think I can upgrade my Powermac g4 400mhz-1.5 ghz. Am I pushing my luck here?Hi! I think you can replace the CPU with the one from Gigadesign (http://www.gigadesigns.com/), Sonnet (http://www.sonnettech.com/) or Powerlogix. They offer up to 1.8GHz drop-in replacement CPUs but you have to ask folks who had experience with them. I replaced one in Gigabit Ethernet for Dual 1.47GHz. It just worked. Try to open a new thread or look for existing one. There is a CPU upgrades database on xlr8yourmac (http://forums.xlr8yourmac.com/cpureview.lasso)

rmanger

Mar 17, 2005, 06:42 PM

Great job, lbodnar and MrFX! I will try to overclock my eMac soon. Wish me luck on good results!

jspivack

Mar 18, 2005, 12:49 AM

Here is Gen1 eMac (700MHz) running without downconverter board. I have combined 2.5v LM317 regulator and a DCB connector together on a small breadboard. They are just regularly spaced jumper pins. Blindmate connector still needs 12v and 5v supplied to it.

Leo - this rocks! looks like I've got a plan for my easter weekend...

would you mind sketching out and posting a quick schematic of your "homebrew" DCB? Also, what's that molex connector in the upper-left hand corner of the first picture connected to?

thanks so much
Jeff

rmanger

Mar 18, 2005, 01:44 AM

I've done it! I've overclocked my Gen3 eMac to 1.5GHz!

Here's some real-world results for you folks out there. I tested using Unreal Tournament 2004 v3355, measuring average FPS using the Santaduck benchmark.

The test hardware is:

1GB RAM
Radeon 9200 w/ 32MB VRAM
MacOS 10.3.8

The test config is:

Gametype: Botmatch
Map: DM-Antalus
Resolution: 640x480
Graphics: Minimum settings

Avg. FPS @ 1.25GHz: 36.43 FPS
Avg. FPS @ 1.5GHz: 39.62 FPS

Overall Speed Increase: 8.76%

I thought I'd get more FPS, so it leaves me a bit disappointed. However, the difference in visual speed was noticeable enough that I could say it is not a placebo effect, especially at the speedier parts of the test.

Unfortunately, the FPS at 1.5GHz is still processor bound. Overclocking the 9200 using ATIccelerator II showed no improvement in FPS.

Some good news: XBench doesn't crash my eMac at 1.5GHz.

I also tried overclocking at 1.67GHz and 1.75GHz, but neither worked. In fact, the eMac didn't start up at all, not even making the startup sound.

Also, it seems like the Gen3 eMacs have the same voltage control chip as the Gen2 eMacs. lbodnar, do you think that increasing the Vcore voltage would let me get these higher speeds? Or is this just a case of my processor reaching its limit?

lbodnar

Mar 18, 2005, 12:29 PM

would you mind sketching out and posting a quick schematic of your "homebrew" DCB? Also, what's that molex connector in the upper-left hand corner of the first picture connected to?I recommend using ready made ATX motherboard power extension like this one (http://www.directron.com/atxextension.html). It is cheap, prewired and colour-coded. Pinout can be found here (http://pinouts.ru/data/atxpower_pinout.shtml).

Both resistors must have the same value.

Capacitors on LM317 in/out pins are not necessary but if you wish, anything from 0.1uF to 100uF will do (from IN to Gnd and from OUT to Gnd).

Molex connector is connected to blindmate connector - you still need to supply 12v and 5v to it as described here (http://forums.macrumors.com/showthread.php?p=1317105#post1317105).

Green wire is ATX power_on, it turns ATX PSU on when grounded. I meant to connect it to some sort of a switch. I am not sure if eMac can control PSU as I still think it needs more then just trickle 5v to power up. Meanwhile this is work in progress...

Correction to the diagram: there are four +5v wires on ATX connector, not two...

madmaxmedia

Mar 18, 2005, 02:24 PM

Hey Leo,

Thanks so much for posting the G3 eMac jumpers! I have one of the educational 1 GHz eMacs ($549 from Apple.com), so going to 1.5 will make a great difference for me...

Thanks again!!!
Steve

lbodnar

Mar 18, 2005, 07:10 PM

I am really interested to see how far Gen3 eMacs can go!

...By the way this thread has become the most viewed one in hardware forum. We must have generated some interest! The thread has accumulated so much unique eMac-related stuff that I start to think it could be a good idea to locally archive it to a CD. If you remember we totally lost Gen1 overclock guide until BigBadMac rewrote it himself again.

rmanger

Mar 19, 2005, 02:37 PM

Yes! Now my Gen3 eMac is running at 1.58GHz!

And it displays the correct information in the About This Mac menu!

Getting my eMac to this level was definitely an adventure. I had to up the Vcore to 1.450V to get the eMac to work. Here's some data:

1.25GHz, 1.350V (Original Settings): Works stable

1.5GHz, 1.350V: Works stable

1.58GHz, 1.350V: Kernel panic on startup
1.58GHz, 1.450V: Works stable

1.67GHz, 1.350V: No startup
1.67GHz, 1.450V: Kernel panic on startup
1.67GHz, 1.475V: Kernel panic on startup
1.67GHz, 1.500V: Works, but unstable
1.67GHz, 1.550V: Works, but unstable

From the data, it seems like 1.5GHz is the maximum clock speed one can achieve at the original 1.350V setting. Higher clock speeds can be achieved by increasing the Vcore voltage. This supports what lbodnar said in a previous post. Also, 1.67GHz @ 1.500V was a little more stable than 1.67GHz @ 1.550V. This is probably just a heat issue, so anyone who got a better processor than me could probably get 1.67GHz.

So was all that work for that extra 80MHz worth it? I used UT2004 again with the same config as before, and here's the results:

Avg. FPS @ 1.58GHz: 40.56

Overall Speed Increase (from 1.25GHz): 11.34%

lbodnar

Mar 19, 2005, 03:14 PM

Yes! Now my Gen3 eMac is running at 1.58GHz!
And it displays the correct information in the About This Mac menu!
...without nvram patch?

Thank you for very detailed information, rmanger!

Does anybody know if Gen3 eMacs use 7447A or 7447B CPU?

MrFX

Mar 20, 2005, 07:21 AM

Hi again,

Leo, have you tried to power the CPU with 5V?

I can get a cheap, little PSU, which has a 5V output of 18A an 12V only 3A.

See you...
MrFX

lbodnar

Mar 20, 2005, 07:25 AM

Leo, have you tried to power the CPU with 5V?Yes, I did. I also thought that it might be easier on some PSUs so I tried and it works just as good as 12v. I can see no difference. The controller chip is specified for operation in 4.5...14v range.

rmanger

Mar 20, 2005, 03:39 PM

...without nvram patch?

Nope, I didn't need to patch anything. The system just recognized the processor speed automatically!

vga4life

Mar 25, 2005, 01:43 PM

lbodnar

Mar 25, 2005, 02:06 PM

topgunn

Mar 25, 2005, 03:12 PM

I have not seen this published anywhere yet, so I will mention that eMacs use ATA-4 on HD connector and ATA-3 on CD drive connector (even without the CD drive attached) so the third HDD on this bus will have pretty low data peak transfer rate - around 10MB/sec as opposed to two others on ATA-4 (I have around 30MB/sec there).

Looks like ATA-4 speed is limited by drives themselves but with ATA-3 it is bus-restricted...
I cannot recall the setup on my 2G eMac but I am 100% certain that the 3G eMacs use an ATA-6 bus for the HDD on the CPU side and an ATA-3 bus for the optical drive.

ATA3 = up to 33mb / sec.
ATA4 = up to 66mb / sec
ATA5 = up to 100mb / sec
ATA6 = up to 133mb / sec

netjosh_granada

Mar 25, 2005, 07:48 PM

So, has anyone started on an eMac ATX conversion yet? I notice the size, unusual configuration, and strange shape of the emac logic board probably require a full-size ATX case with ultra-tall standoffs (probably homemade with screws and tubing or nuts).

I'm waiting for my financial situation to stabilize a bit before plunging in but I can't wait to remake my mild-mannered 3G eMac into a dual-LCD, triple-HD, dual-layer superdrive-equipped monster.

I'm already planning a great case mod with my 1G eMac and a 2nd hand Power Macintosh 8500 tower I've bought on eBay.

I've always been a fan of old-school Power Macintosh's design and I'm planning a complete internal reestructuration of this Powermac 8500, but keeping it's great external design.

The computer I'm planning will be as follows:

Power Macintosh 8500 tower.
eMac 1G 700 Mhz@1000 Mhz (if possible...).
512 Mb PC100 SDRAM (PC133 if I manage to overclock FSB).
LG 16x Dual Layer DVD Writer.
Iomega Zip 250 drive SCSI (comes with PM8500 -> needs SCSI to USB/Firewire adapter).
2 x 80 Gb HDs in RAID 0 mode.
300 Watt ATX Power Supply.
2 x 8 cm fans running at 7v or even 5v (i'll see) on the top of the case (where ATX PSUs usually goes) to keep everything cool.

To cool the CPU, I plan to use a standart Pentium 4 heatsink (see Arctic Cooling (http://www.arctic-cooling.com/cpu2.php?idx=23&disc=)) but adapted (cutted and drilled in certain areas) so that it can be used in this strange motherboard.

Well, I will keep you informed on this project as soon as the PowerMac comes, and as soon as Lbodnar finishes the GREAT JOB (Thank you leo :D :D ) he has made powering up my emac mobo in a way I would have never thought possible (I'm talking about running it without DCB...).

See you all...

** NetJosh **

jspivack

Mar 26, 2005, 04:23 AM

hi Leo

So I'm going to the electronics store this afternoon to pick up components for my replacement DCB so I can power my Gen1 eMac from ATX PSU only, bypassing the Apple DCB and powering the drives from the ATX PSU.

In the initial board schematic (http://forums.macrumors.com/attachment.php?attachmentid=21689), you show 2 capacitors and 2 resistors; these are also shown in the photo (http://forums.macrumors.com/attachment.php?attachmentid=21694).

In the second version, the schematic (http://forums.macrumors.com/attachment.php?attachmentid=21906) shows 2 resistors 0 capacitors, while the photo (http://forums.macrumors.com/attachment.php?attachmentid=21908) shows 2 resistors and 1 capacitor.

so, uh, which one is right? The documentation from NatSemi (attached) seems to indicate that one or both of the caps are optional...

thanks
jeff

jspivack

Mar 26, 2005, 04:34 AM

Post #371:By the way can anybody quote definite Firewire standard on cable power? I have seen anything from 8v to 38v and even ridiculous quotes like 1.5A at 40V (that's 60w of power!) Macs traditionally supply around 15v..18v on their Firewire cable but I try to get lower to something like 11V by using only 12v PSU voltage. Portable drives and iSight are OK with that but I really want to see a standard figures...

Post #387:yes, yes, Yes!

We can throw downconverter board away. eMac will run without it!

I have temporarily tapped in power by soldering directly to the reverse side of DCB connector on the logic board and it powers up and works! My impromptu 5v->2.5v converter (see post number 379 above) gets pretty hot so I might use a better heatsink in the final version but schematic will stay the same (I have used LM317T - can't remember how it is different from LM317A or LM317, was it Vout precision?)

I supply +12v, 5v, 3.3v off a standard 120W ATX power supply.

Leo

does your headless version have powered firewire? if so, are you getting it from ATX PSU? How are you patching it in?

thanks

jeff

jspivack

Apr 10, 2005, 10:52 AM

Leo

I tried making my own replacement DCB for Gen1 eMac this weekend, but it isn't quite working:

I followed your schematic from post #404, with R1=R2=470 ohms.

without load, I get 150mV on pin 13 and 4.5V on pin 11 rather than 2.5V on each one. Any ideas why that might be?

Thanks

Jeff

jspivack

Apr 10, 2005, 11:54 AM

without load, I get 150mV on pin 13 and 4.5V on pin 11 rather than 2.5V on each one. Any ideas why that might be?

Thanks

Jeff
I figured this out - i must have misinterpreted your schematic or something - you need to put R2 across pins Vout and Adj of the LM317. So that's OK. My homemade DCB has all of the correct voltages as indicated in schematic of post 404.

But the eMac is not powering up. (Gen1/800Mhz)

I have an ATX PSU hooked up to my homemade DCB, plus am powering the drives directly from the PSU. I've got a switch on the green wire of teh PSU to turn the PSU on and off. The main power switch on the eMac is busted, so I attached a couple of wires to try to turn the mobo on and off - but I'm not sure of the wiring there, so it's a bit of a shot in the dark.

And it's not powering up.

I have nothing connected to either of the blind-mate connectors, and nothing connected to the video connector. does anyone have any ideas?

Oh - when I got the computer, it was dead. the problem was allegedly with the analog board, but I can't rule out that it's the mobo that's dead.

thanks

jeff

Tim Deh

Apr 17, 2005, 10:09 PM

With much thanks to BigBadMac, my eMac works again!

Hi,

I have the same problem as you, but I can't find your solution in this thread.
I've oc'ed my eMac 700Mhz to 850Mhz (removed 1 jumper). When I reboot, I only can hear the 'chime', monitor "starts up", but no video signal.

I've already reset the Pram, removed battery,...Etc

Can you post your solution please?

gothicspikey

Apr 18, 2005, 05:56 PM

firstly, thank you leo for ur great guide :) i'm now running my 800 emac at 1.33ghz :D, but i have a question regarding graphics on the emac

On most PC's i've seen onboard AGP graphics use system memory istead of having its own ram, is there any way possible to like use 256mb or whatever of ram from the system memory instead of the 32mb that the emac has? i have absolutly no idea on this matter, thats why am asking really, if it was possibly that'd be so great lol

thanx in advance

Plastic Chicken

Apr 18, 2005, 11:11 PM

Hi,

I have the same problem as you, but I can't find your solution in this thread.
I've oc'ed my eMac 700Mhz to 850Mhz (removed 1 jumper). When I reboot, I only can hear the 'chime', monitor "starts up", but no video signal.

I've already reset the Pram, removed battery,...Etc

Can you post your solution please?

Give me your email address...I'll forward stuff to you.

I'm surprised this thread is still alive :)

vga4life

Apr 19, 2005, 11:40 AM

On most PC's i've seen onboard AGP graphics use system memory istead of having its own ram, is there any way possible to like use 256mb or whatever of ram from the system memory instead of the 32mb that the emac has? i have absolutly no idea on this matter, thats why am asking really, if it was possibly that'd be so great lol

What you're describing is not desirable. "More video ram" doesn't make the GPU faster. First, onboard video controllers that steal system ram are way, way slower than GPUs with dedicated RAM. Second, the whole point of AGP is to provide a fast pipe from system memory to video memory. In a sense, your emac is already capable of using, when necessary, system memory. This is better than the GPU being required to use (much slower) system memory.

-vga4life

gothicspikey

Apr 19, 2005, 04:59 PM

thanx for clearing that up for me :)

netjosh_granada

Apr 22, 2005, 09:47 AM

Hello everybody,

as you might know, I sent lbodnar my G1 emac motherboard to see if he was capable of making it work. He did a great job powering it up, and a couple of weeks ago he sent it back to me.

Now, I'm proud to tell you all that I've broken the Gigahertz barrier with my 700 Mhz eMac, and most important, at STOCK VOLTAGE. One of the things I've had to change is the stock cooler, and now I'm running it with a Pentium 4 All-Copper Heatsink and a 80 mm fan running at only 5v, wich is all it needs to stay cool even running Folding@Home 24/7.

I'm finishing my case mod for it, and as soon as I finish it, there will be some pictures here to let you see my eMac system.

gothicspikey

Apr 23, 2005, 02:05 AM

right i know this may sound completly stupid, but is it possible to change the L2 cache at all, the cache on my emac is 256, but i think on the new emacs the cache is 512, just wondering if it was possible, and if so how would u do it?

thanx xx

vga4life

Apr 25, 2005, 01:28 PM

Now, I'm proud to tell you all that I've broken the Gigahertz barrier with my 700 Mhz eMac, and most important, at STOCK VOLTAGE. One of the things I've had to change is the stock cooler, and now I'm running it with a Pentium 4 All-Copper Heatsink and a 80 mm fan running at only 5v, wich is all it needs to stay cool even running Folding@Home 24/7.

Extraordinary work! How did you attach the new heatsink?

-vga4life

pmartin

May 4, 2005, 05:39 PM

Hey, I was wondering if anyone could sell me the required connectors for this. If so send me an email at pauldmartin @ gmail dot com. I have a genartion 1 emac, and I have the DCB although it would be preferable to use the connector above instead. I just don't have the soldering skills to build these connectors myself.

rmanger

May 14, 2005, 06:15 AM

Well, after using my 1.58GHz Gen3 eMac, I've deemed it less stable than it needs to be. Less stable in this case means 1 kernel panic about every 3 weeks. My rate of kernel panics was much lower before the overclock, about 1 panic every 6 months. The reason why I caught on to the instability was when my eMac embarassingly kernel panicked at a recent LAN party during the screensaver!

So I've turned the Vcore voltage down to 1.425V, hoping this will improve stability. It seems to work, for now...

Here's the updated list:

1.25GHz, 1.350V (Original Settings): Works stable

1.5GHz, 1.350V: Works stable

1.58GHz, 1.350V: Kernel panic on startup
1.58GHz, 1.425V: Works stable
1.58GHz, 1.450V: Works fairly stable

1.67GHz, 1.350V: No startup
1.67GHz, 1.450V: Kernel panic on startup
1.67GHz, 1.475V: Kernel panic on startup
1.67GHz, 1.500V: Works, but unstable
1.67GHz, 1.550V: Works, but unstable

lbodnar

May 14, 2005, 09:19 AM

...
And it's not powering up.
...
jeffJeff, (and others)

You still have to use eMac's power button to switch it on!

I had quite a few emails about that. The PC PSU provides the power all the time even when the eMac is off or asleep. This is how analog board on eMac works as well, it just drops voltages a little bit (20v->12v, etc)

stolfi1

May 16, 2005, 02:23 AM

hey guys if any of you have the old emac casing left after your mod I need to buy one i would prefer it come with the power cable to please pm with your price.Sorry if this post is unwelcome

rmanger

May 16, 2005, 04:18 AM

After testing out 1.58GHz @ 1.425V Vcore, I've convinced myself of two things.

If you care about stability:
DO NOT MESS WITH THE VCORE VOLTAGE.
DO NOT OVERCLOCK PAST 1.5 GHZ!

This comes as a result of a kernel panic while using TextEdit. :(

Since I don't want my computer crashing in TextEdit or screensavers, I've decided to just clock back down to 1.5GHz and reset the Vcore back to its original 1.350V. This seemed to be the most stable back then anyways, since I have never experienced an inkling of instability with this config.

Maybe I just didn't get a lucky processor, or maybe it's a software conflict. Who knows. I guess I should be happy that I got a 20% speed boost for free... :o

Rod Rod

May 16, 2005, 12:43 PM

I guess I should be happy that I got a 20% speed boost for free... :o
May the time you spent on the mod be more than gained back by the time you save by making your machine faster. BTW that's pretty brave of you to take an eMac to a LAN party. Did you transport it in a custom wheeled case?

rmanger

May 16, 2005, 06:14 PM

No custom wheeled case. Just old fashioned lifting with the arms. :)
After a while, you get used to carrying it one handed while unlocking your car door...

My friends and I are not really heavy gamers. The fastest machine is an AMD FX-53 3200+ w/ Radeon 9800 All-In-Wonder Pro. Of course, my machine is the slowest :( , but we still have fun playing WarCraft III (and lots of it), UT2004, Diablo II, and the like.

But I did feel better when my friend's younger brother brought a 1.7GHz P4 machine last Saturday. I didn't have the slowest machine that day for sure!

skibummer

Jun 8, 2005, 05:45 PM

Just like to let you know that I just over clocked to 1.27 (1.266) from 1ghz. It seems stable enough, no crashes or kernal panics, with video compression, itunes and seti@home going on at the same time for hours. Thanks for the great instructions. Xbench rating up 20 points!

netjosh_granada

Jun 12, 2005, 04:07 PM

-vga4lifeQuote:
Originally Posted by netjosh_granada
Now, I'm proud to tell you all that I've broken the Gigahertz barrier with my 700 Mhz eMac, and most important, at STOCK VOLTAGE. One of the things I've had to change is the stock cooler, and now I'm running it with a Pentium 4 All-Copper Heatsink and a 80 mm fan running at only 5v, wich is all it needs to stay cool even running Folding@Home 24/7.

Extraordinary work! How did you attach the new heatsink?

-vga4life

As I'm using the eMac logic board on a new case, this Heatsink mod was something necessary because I didn't want the standart Heatsink to take a lot of space in the new case apart from being more difficult to install a fan on it.

This is how I did it:

Buy a standart Pentium 4 Heatsink (the better the squarest and flatest) and three screws to attach the Heatsink to the logic board.
Mark the holes available around the CPU on the Heatsink.
Drill the three holes on the Heatsink carefully, because an error can drive it unusable because of a displaced hole.
Apply some thermal grease on the CPU.
And attach the Heatsink carefully, tightening the three screws to the logic board trying not to crack the CPU core.

This is how I installed a standart Pentium 4 heatsink and that is how it looks:

maxpayne.co.uk

Jun 13, 2005, 03:25 AM

Deleted.

wernerru

Jun 23, 2005, 09:30 PM

shadowmoses

Jun 24, 2005, 05:06 AM

I think 1.6mhz from 1ghz may be one of the biggest OC's an eMac has seen..

ShadOW :cool:

seb_carley

Jun 25, 2005, 11:43 AM

Just curious as to what the fastest everyone's pushed their eMac's so far? i'm still wondering if mine was just a fluke that it took 1.6 from 1.0 without a problem (2nd gen). be cool to see what the different proc's are capable of

1st post (user since 1997: Newton 120, Performa 5400, iMac indigo 450MHz) Hi all!

Been reading this thread since getting my 3G eMac (1.25GHz 7457 v1.1 (tech 0)) last summer. Had a slow day at work yesterday so I read the entire thread again and looked at leo's site.

Have taken the plunge and removed R270 and R673 (to get to 1.58) with a swiss army knife!

No boot sound - blank screen!

<heart sinks>

cracked open again and removed R689 (for 1.5).
reset PMU.
<prays>

boot sound like music to my ears (so good I zapped PRAM to hear it again:))

ATM reports 1.5GHz but kernel panic after 10 minutes. shut down, go for walk, return and boot. So far (30 mins) so good but haven't done anything too proc-intensive yet.

phew!

So now I'm interested in getting a Zalman variable speed fan controller (not too sure how stable it'll be if it runs hotter though), had a look at the site (http://www.macbidouille.com/article.php?id=123) describing how to install and would appreciate anyone who's done it giving a quick english guide (google translation not so good) on how easy this is (preferably with a swiss-army knife :) ).

now to compress some VIDEO_TS...

cheers

madmaxmedia

Jun 25, 2005, 12:41 PM

maxpayne.co.uk

Jun 25, 2005, 01:09 PM

Installing the fan is easy, much easier than the work you've already done.

After you get the fan and open your eMac up again, you see pretty easily where you need to shave off a bit. It will take you all of 5 or 10 minutes, I think I used a steak knife.

BTW, when you OC'ed your G3, you didn't have to remove the heat sink or anything right? I'm going to do mine soon as soon as I summon the time and courage. I've already swapped out my HD and optical drive, so disassembling is old hat for me. ;)
You have to remove the logic board, but not the heatsink on the CPU.

BTW, removing the jumpers with the knife probably wasn't a good idea because it may remove the metal track which will disallow you to underclock it again if the system is unstable.

madmaxmedia

Jun 25, 2005, 01:10 PM

You have to remove the logic board, but not the heatsink on the CPU.

BTW, removing the jumpers with the knife probably wasn't a good idea because it may remove the metal track which will disallow you to underclock it again if the system is unstable.

Thanks for the info.

I didn't use a knife to remove the jumpers, I used it to shave the plug to make the variable fan speed controller fit. :)

I'm going to OC my eMac next, but will leave the steak knife in the drawer. ;)

seb_carley

Jun 25, 2005, 01:31 PM

Thanks for the info.

I didn't use a knife to remove the jumpers, I used it to shave the plug to make the variable fan speed controller fit. :)

I'm going to OC my eMac next, but will leave the steak knife in the drawer. ;)

Nah, I think he meant it was a bad idea for me.

As it happens, I just slipped the tip of a blade under the jumpers and popped them off, the silver blobs either side remained intact. (lucky they do, I had another kernel panic and am possibly going to step down to 1.42...)

fun this!

cheers

seb_carley

Jun 25, 2005, 01:39 PM

You have to remove the logic board, but not the heatsink on the CPU.

Lucky really, I saw two heatsinks, a standard looking black knobbly one (I think on the GPU), and a huge weird (permanent looking) chunk of copper leading to a copper bar/pipe extending past the back of logic board to a series of heat dissipation plates next to the fan.

Never seen much like that before. (but then I never looked).

2rc I had to remove the combo drive, unscrew the logic board mounting, disconnect the video, speaker cables and pull the logic board out - easy. :)

seb_carley

Jun 26, 2005, 07:44 PM

Hi again

System is super unstable at 1.5GHz, have had at least 20 kernel panics since OC yesterday.:eek:

Picking up a soldering iron tomorrow to take me down to 1.42 but wondered:

Is this likely to be a heat issue? If so what's the best way to install a small fan?

Would adjusting vCore make me potentially more stable at 1.5? If so what jumpers to remove on vCore chip? (i downloaded the pdf)

Come on! Help the stupid!:)

Cheers

shadowmoses

Jun 27, 2005, 01:27 PM

Adding more fans is not an option, and i dunno about the vBench scores...
Maybe you should just put it down to 1.42..

ShadOW :D

seb_carley

Jun 27, 2005, 03:09 PM

yeah, have now underclocked to 1.42.

with a sooty and bashed piece of crap soldering iron I borrowed from work! and a cup of strong black coffee making my hands shake all over the place(whisky would have been better) :)

seems stable enough for now, I think crashes at 1.5 were heat related.

wish me luck.

<edits sig>

madmaxmedia

Jun 30, 2005, 01:14 PM

topgunn

Jun 30, 2005, 01:32 PM

How would a 1.42 or 1.5 GHz eMac compare to a 1.6 GHz G5 iMac?

From searching around the web, it seems the G5 is only slightly better per clock cycle than G4 for most stuff. Meaning that a G5 with 10% higher clock speed than G4 will do most things about 15-20% higher (with some variations of course.) That was surprising to me since everyone complains about how slow the bus speed is on the G4's...

I was considering the idea of buying one of the G5 iMac refurbs at Apple.com for $999. But if it's only marginally better than a 1.5GHz eMac then I probably won't bother. The main improvement would be the screen and form factor.

I guess it depends on what EBay value for a 1.5GHz/120GB/512MB/SuperDrive eMac is...
The greatest difference in speed is found in the GPU, FSB, memory, and SATA not in the CPU. The a 1.5GHz G4 would be similar to a 1.6GHz G5 overall though each has their strong suits. The other features of the iMac would be where it pulls away from the eMac. Though the 1st gen iMac G5 did have the bum SATA controller and now the eMac has a 9600 GPU so the difference between a new eMac and a 1st gen iMac G5 is minimal.

madmaxmedia

Jun 30, 2005, 01:51 PM

The greatest difference in speed is found in the GPU, FSB, memory, and SATA not in the CPU. The a 1.5GHz G4 would be similar to a 1.6GHz G5 overall though each has their strong suits. The other features of the iMac would be where it pulls away from the eMac. Though the 1st gen iMac G5 did have the bum SATA controller and now the eMac has a 9600 GPU so the difference between a new eMac and a 1st gen iMac G5 is minimal.

Thanks for the scoop! Did you OC yours yet?

I guess I'll still consider the switch, but not for performance. The 17" widescreen LCD sure looks nice... (plus the overall look...)

topgunn

Jun 30, 2005, 02:29 PM

Thanks for the scoop! Did you OC yours yet?

I guess I'll still consider the switch, but not for performance. The 17" widescreen LCD sure looks nice... (plus the overall look...)
I sold it and bought a Rev B 20" iMac.

madmaxmedia

Jul 3, 2005, 03:38 AM

I sold it and bought a Rev B 20" iMac.

Congrats! How do you like it so far?

I am now considering a Rev. B 17", it's only $1195 AR from Amazon right now. The Rev. B has so much extra stuff that even good used Rev. A's don't seem to offer as much value.

About the only thing that I might actually need the faster hardware is for some iMovie and iDVD. But I'm not sure how much impact it will have.

Otherwise I do really like the 17" widescreen LCD (so I'm also considering a used 17" G4 iMac (USB 2.0) as a cheaper alternative.

seb_carley

Jul 5, 2005, 02:27 PM

Hi people

I've got a Zalman fanmate 2, and installed it (see pics)

problem is, I think I need to cut and rearrange the wires leading to and from the fanmate before it has any effect, currently the knob affects the fan speed not one bit... :confused

currently arranged like:

Mac
Red - Black - Yellow
plug
White - Red - black
fanmate
Yellow - Red - Black
plug
Red - Black - Yellow

Please could someone tell me how I should rearrange the 2nd and 3rd set of wires?

Cheers

Tycho93

Jul 12, 2005, 01:18 AM

I have a Gen1 700mhz emac, and need help getting power to the logic board. Can anyone detail in simple terms how to run power from an ATX power supply to the blindmate connectors on the LB?

kkrouse

Jul 18, 2005, 10:47 PM

Right now my Emac is still clocked at 1.32(up from 800). I have never had any problems with it. No kernal panics, no overheating:totally stable even when intensively processing video files. All this with no cooling mods whatsoever.
I gig sdram
250 gb internal drive
as well as a three hundred gig ide drive under my desk.
Anywho, I was wondering a couple of things. Has anyone been able to figure out a way to get digital video signal out of the ATI chipset. Switch Res X allows me 1600 by 1200 resolution on my flatscreen in analog, but the screen also supports dvi. I know the ati card supported digital output in all its other incaranations, but just seems to lack the connector. Did anyone figure out what that unsed plugin socket on the board was? Diagnostics? I was also wondering if software raid actually gives any performance increase as I could dump the cd rom connection and hook up another matched drive on that ide port.
Finally, though this is a little off topic. I bought 32 imac 350s for my clasroom from another corporation(we could have had them for free but that is another story) I tried to overclock one to 600 mgz but it would not boot, chime, nothing. I tested all the voltages that Apple's technician's guide gave for diagnostics and they were all spot on. When I reset the jumpers to stock, it booted up and ran just fine. Does anyone know if there are any memory timings, or voltage settings that also have to be set for this to work. A site that was mentioned earlier in the thread gave me the jumper table, but it was real skimpy on everything else. My goal is to get these all up to mac os x. Any help anyone can give me would be great. I have spent $12,000 of my own money this last year and created a classroom better than that in most universities, but I have just put 4 of my own kids thougth college so anything I can do myself I need to learn.
Also as a side note I discovered that if I format a 300 gb ide drive with my emac and disk utility an exact bootable clone of the Os, it will boot and run in the couple of Imac Special Ed. DVD g3's (400 -600) I have and maintain their full capacity. I have filled up the full capacity of these disks with video data and they run perfect and fast(7200 rpm). as compared to the little 20gb-40gb( maybe 5400 rpms) they came with. The only downside is that I cannot ever use the G-3's disk utility to fix permissions or anything of that sort or the bios tells on me and the disk is suddenly recognized only as 120 gb and fills only to that level with data. Anywho, of all the things I have blathered on about, my overclocking of g3 350's is my biggest need right now.

TY

Jigglelicious

Jul 18, 2005, 11:10 PM

I would *NOT* recommend you overclock the iMac's to 600mhz. Those old convection cooled iMac's get very hot, and even 500mhz is unlikely. Try for 400mhz and maybe 450mhz (my iMac was able to get to 450mhz), but anything higher than that is just asking for trouble.

kkrouse

Jul 19, 2005, 10:43 PM

Hi I think you are right in terms of the cooling issue. 450 ish sounds about right. The reason that I aspired for 600 was I had found a page that showed how to make a custom heat sink and fan for this unit but I wanted to see if it would even boot. As you read above it didn't. The jumper charts I used were at the link below. Did you use a different chart than those? And do you think any other settings needed to be changed even for 450 as most of this guy's site is dead link city?
ty

http://www.bekkoame.ne.jp/~t-imai/imacde1.html

Jigglelicious

Jul 19, 2005, 10:51 PM

That was the exact same website that I used. I managed to OC my 350mhz iMac to 450mhz without any problems. Well actually, I had a ton of problems, but that was related to my soldering job, not related to heat.

Most people recommend overclocking small steps at a time, until you find the highest rate at which your computer can run safely. I ran my iMac for 24 hours while simultaneously playing an Audio CD and having the iTunes visualizer on, to stress the maximum amount of heat the computer would ever create. Remember, just because the computer can boot and operate at a higher speed does not mean that its stable at that speed. The computer must be stress tested to make sure it operates under the most extreme conditions.

mbdamdg

Jul 20, 2005, 11:40 AM

I just overclocked my iMac 400 DV to 500 mhz without too much trouble considering it was my first soldering job ever. It only took about 15 min. I would think you could get those 350 mhz iMacs up to at least 450 without much trouble. I'm running 10.2, and while it isn't the fastest (especially compared to my 3 GHz XP box) it works well enough.
Good luck!

madmaxmedia

Jul 20, 2005, 12:25 PM

I will be opening my eMac hopefully in the next couple of days to put in new HD, DVD burner, and overclock as well. I put in a fan speed controller previously, and will check the colors.

Funny thing is that I didn't need to change the wiring, just modified the plug to make it fit and it worked perfectly. I don't remember if it was a Zalman Fanmate 2, but I thought that it was.

I wonder if there's a chance that you fanmate is actually defective?

Hi people

I've got a Zalman fanmate 2, and installed it (see pics)

problem is, I think I need to cut and rearrange the wires leading to and from the fanmate before it has any effect, currently the knob affects the fan speed not one bit... :confused

currently arranged like:

Mac
Red - Black - Yellow
plug
White - Red - black
fanmate
Yellow - Red - Black
plug
Red - Black - Yellow

Please could someone tell me how I should rearrange the 2nd and 3rd set of wires?

Cheers

madmaxmedia

Jul 24, 2005, 03:16 AM

Okay, I finally cracked open my eMac again for some new stuff-

1. OC'd to 1.33GHz. Not as high as I originally planned, but since I had a edu 1GHz model I only had to solder 1 bridge. After I saw how miniscule the bridges were, I decided discretion and 1.33GHz was better than a nun-functional eMac (if I had a thinner soldering iron and some sort of magnifying glass I would have been more bold.)

Good news is that the computer is humming along at 1.33GHz, nice enough for me! Thanks to Leo and everyone else here for all the great info and tips!!!

2. Added a dual-layer burner ($50 from Newegg) and new 200GB HD.

3. I looked at my Zalman fan controller wiring. I'm not sure if I have the #1 or #2 model, but it shouldn't matter. Basically all I did was shave a bit of plastic to make the plugs fit (as it seems most do), but here is the wiring for Seb:

Fan side

* Mac yellow to Zalman black
* Mac black to Zalman red
* Mac red to Zalman white

Power side

* Mac yellow to Zalman black
* Mac black to Zalman red
* Mac red to Zalman white

As you can see, it's basically symmetrical.

BTW- for those who have done this mod, how low have you turned down the fan? I am now at 50% or so. The fan is quieter than before, but I wouldn't mind going lower if its okay...The G4 iMacs were really quiet and have similar hardware (although airflow was of course different.)

Actually, I should fool around the controller to make sure it is actually reducing fan speed/noise, and not just some placebo effect! ;)

madmaxmedia

Jul 24, 2005, 03:22 AM

seb_carley

Aug 7, 2005, 05:38 AM

Now I'm wondering if my fan speed controller is working at all. From the original mod page there is a schematic of how it should be wired. The problem is that the wire colors in my eMac are not the same as in the schematic.

http://translate.google.com/translate?u=http%3A%2F%2Fwww.macbidouille.com%2Farticle.php%3Fid%3D123&langpair=fr%7Cen&hl=en&ie=UTF-8&ie=UTF-8&oe=UTF-8&prev=%2Flanguage_tools
http://www.macbidouille.com/articles/regulateur-zalman/schema.jpg

Can anyone help with this?

Leo told me how to rewire a fanmate 2, here is a photo of the rewiring, and the message he sent me. My fan is now inaudible.
quoth Leo:
Hello!

Thank you for emailing me. I am glad you have used my information.

You are correct, colours do not match. You have to rearrange wires so that red/red black/black and white/yello are connected together.
It is also important to mention that Fanmate has power side going into its SOCKETS and coming out of its PINS. eMac has the opposite arrangement so you have to find the way to connect male emac plug to male Fanmate plug, same with female plugs.
One way would be to cut and swap around Fanmate connectors.
It is easy as soon as you figure it out!
Remember: red is +12v, black is ground, white/yellow is RPM sensor.
Fanmate gets its power on its female side (should be illustarted on its box)

Does this now fall together?

end quote

In the attached photo I cut the fanmate wires in half and re-ordered them as shown. I soldered them together, taped them seperately and then taped the lot together.
I wish you success, this is certainly worth doing and has no ill effects (have been compressing VIDEO_TS all day in the middle of a heatwave with no crashes...)

shadowmoses

Aug 9, 2005, 03:07 AM

hey, i just did the re-wiring in my eMac as you have shown above for the fan-mate 2......and now my eMAC's internal fan has stopped functioning all together with or without the fan mate connected, the fan doesnt even spin when i use the normal out of the box coonection with no fan controller installed...

I am not sure what has happened but i assume the re-wiring you showed didnt work on my eMac and blew a fuse or something as it seems like my fan is broken....

Do you have any ideas of how i could get my eMac's fan spinning again???

Thanks,

Shadow ;)

the_new_guy

Aug 17, 2005, 10:46 AM

hi all,
i wanted to change the FSB on my SEcond gen eMac can some one help me

thanks
the_new_guy

bvz

Nov 12, 2005, 02:11 PM

Hi all!

This is the coolest thread ever. And maybe I can wake it back up a couple of months later :)

First off I'd love to hear any "3 months later" stories of your systems. Did you ever get them into a case? Are they still running? Any new mods?

Also, I'd love to say special thanks to all of you who did so much work so that I can just walz in here and start playing (esp. lbodnar and MrFX!). I know next to nothing about electronics so all that investigation would have been way way beyond me.

Ok, so this is where I am...

I have just gotten my hands on a 1st generation eMac (I guess that means 700 MHz, eh?). It apparently won't boot or start up even so I figured I'd take a stab at getting it back up and running and make it headless while I am at it. I liked the idea of cramming it into a CD player case so that is my plan (if I get it running).

And here is my question...

With the atx power supply (and the circuit designed by lbodnar) can the system go into deep sleep? That would be a huge plus for me since I plan on having the system as part of my living room stereo system and don't want to shut it off whenever I am not listening to it. I'm still planning on the coversion, I'm just curious.

Thanks!

DSL Steve

Nov 12, 2005, 02:18 PM

Deleted, wrong forum

bvz

Nov 13, 2005, 08:38 PM

Ok, I wound up purchasing a Mac Performa 6115CD because it is already set up with a space for an optical drive, hard drive, and a power supply. I suppose I could use the built in power supply if I figure out it's pin outs right? It is advertised on the top that it puts out +12V 2.5A, -12V .5A, and +5V 11.5A... but it also says something about AC output. Hmmm. I am really new to all of this.

I might be better off buying a new micro atx power supply. Can these power supplies be put to deep sleep?

I'll keep posting as I figure stuff out (or don't :) )

Ben

bvz

Nov 17, 2005, 11:05 PM

Seems like I am the last one at the party :(

Ok, so far I have been researching atx power supplies. I still have not been able to figure out if they go to deep sleep or not. I also don't know what kind of a signal the eMac sends out to indicate that it wants the PSU to sleep.

I have found some truly interesting docs on how these things work in general though. The following is very usefull:

http://www.pcguide.com/ref/power/sup/index.htm

and for some decent docs on the ATX spec as well:

http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf

I am still curious if anyone here... well curious first whether there IS anyone here :) but also curious whether anyone here has gotten their rig to work and whether it goes to sleep or not.

I also want to know about grounding the motherboard. I have some zinc bolts which I am using to attach the motherboard to the case... do I need to have a connection on each and every bolt hole that the original eMac used (the ones with the metal plating on them)?

ben

themacsmith

Jan 2, 2006, 11:35 AM

Jeff, (and others)

You still have to use eMac's power button to switch it on!

I had quite a few emails about that. The PC PSU provides the power all the time even when the eMac is off or asleep. This is how analog board on eMac works as well, it just drops voltages a little bit (20v->12v, etc)

Um, yeah. So I figured out that powering the board directly to the blind connector as mentioned in your previous threads alleviates the need for the DCB. But what about the 2.5v?? I guess that I'll build my DCB replacement per your excellent instructions and go from there.

All I get right now is the PC PSU starts up (fans, voltage etc), and when I press the eMac ON I get a temporary burst of fan activity and nothing else.

Ideas-suggestions???

Thanks
Kim C. - The MacSmith

JonnZ

Jan 25, 2006, 12:43 PM

Hi there!

Thank you all for your information provided to do the eMac conversion

I succesfully soldered all adapter cables (power and video) and connected them.
I also probed them and double-checked them, so my cables are ok.:)

When I now press the power-button, I can hear the start-up chime, all connections(fan, hd, od) have power, but i have no video! Neither on the external monitor out nor on the 18-pin video-connector.
Even the heat sinks get warm. :confused:

Do you have any ideas?:confused:

JonnZ

Jan 26, 2006, 09:29 AM

Yes, I did. I also thought that it might be easier on some PSUs so I tried and it works just as good as 12v. I can see no difference. The controller chip is specified for operation in 4.5...14v range.

@ lbodnar

Hello there!
how do I have to solder the blindmate-connector to run the CPU at 5 v? Which pins have to be connected to 5 V instead of 12 v?

This Information would really help me with my ATX-Conversion because I own an low-noise small fromfactor PSU. But it has just 3A on the 12 V line, which is not enough for the emac. The 5V line has more than enough power, about 12 A or so.

Thank you for your reply!

lbodnar

Jan 26, 2006, 12:25 PM

how do I have to solder the blindmate-connector to run the CPU at 5 v? Which pins have to be connected to 5 V instead of 12 v?Just pins 5 and 7 which are marked C12V should be switched over to +5V. Expect good amperage on this connection (5-10A?).

Pins 1, 3 (downconverter) and 13 (Firewire) have to remain on +12v but they will draw very small current.

Leo

lbodnar

Jan 26, 2006, 12:32 PM

When I now press the power-button, I can hear the start-up chime, all connections(fan, hd, od) have power, but i have no video! Neither on the external monitor out nor on the 18-pin video-connector.
Even the heat sinks get warm. :confused:

Do you have any ideas?It would be very very helpful to have HDD that you can boot off and that will autostart VNC server which allows you to connect to it over the network and see the screen (I used PC as client.) Most probably you have the screen stuck in one of the low resolution modes which results in very high vertical refresh frequency like 100+Hz. It's OK for internal CRT as it was built around these but hardly many external screens can run that high. TFTs are definitely out of question.

Also, try to reset PRAM.;)

JonnZ

Jan 26, 2006, 12:41 PM

You came up with the right idea.

I ran my eMac with 1280x1024. My old CRT in my workshop didn't support that resolution. I plugged in my 17" TFT and it worked.

Of course I had a HDD to boot off, so everything is working now.

I will keep you updated with my work on the eMac.

Spanky Deluxe

Feb 17, 2006, 02:08 PM

Does anyone know where the connector for the emac's power switch (Gen 3) goes? I've just got myself a Gen 3 logic board that I want to run headless but I can't work out how to switch the thing on!! I've made an adapter to connect it to an ATX power supply, its got RAM in it and I have a VGA adapter plugged into an LCD screen. I can't for the life of me work out which pins I have to short to start it up though!!

Ok, I'm pretty sure I've found the power connector now. When I short it the lcd screen comes on for a few seconds and turns off again. Is the output from the mini-VGA output stuck at a high refresh rate in the same way that the on board one is? If it is then I'm a bit buggered. I've got an iBook G3 I could run in target disk mode, how do I do the whole remote changing of resolution trick? Actually that won't work because I'd be using the G3 as a target disk. Bugger.

lbodnar

Feb 17, 2006, 06:07 PM

Actually that won't work because I'd be using the G3 as a target disk. Bugger.Install VNC server on eMac's disk in target mode (boot iBook off it via Option boot) and make it autolaunch. Then boot them both up and log into eMac from iBook or any other computer on the network.

Spanky Deluxe

Feb 17, 2006, 07:42 PM

I worked out how to do it. I started the iBook in Target Disk Mode, connected it to the eMac, booted up whilst holding down Command+Option+Shift+Del so that it booted from the iBook's hard drive (you've got to love the fact that no matter what computer your on you can use the same installation, not like Windows!!). I then formatted the eMac's hard drive and did a disk backup of my iBook's hard drive to the eMac. Restarted and unplugged the iBook and hey presto!! I'm typing on it now!!

I've now got a 1Ghz G4 166Mhz FSB Apple computer for £61. I chucked in some old ram I had lying around, a spare hard drive and dvd drive and found an old ATX power supply and there we go, a super-cheap but very decent Apple computer!! Now all I need to do is sift through this hugely bloated and ageing thread and find the resistors needed to overclock to maybe 1.5Ghz. I'm hoping for 1.33 but with luck will be able to go further. So for £61 I'll have a mac that's of equal specs to a mac mini. Mac minis might be cheap but this is way cheaper. A G4 for £61. That's about $106 for you American folk. Deal, eh?!!

I noticed in the eBay auction it said "Doesn't have an onboard modem" and knew it was going to be an underclocked G3 eMac. I was right. Radeon 9200 and 166 FSB. Nice.

brutus19

Apr 1, 2006, 07:14 PM

Hi guys, I've been lurking around for years now, I don't really have much to say, but now it seems I'm running into a problem.

I've managed to get a 1G mother board and now it is working as a headless mac but I've ran into a problem outputing the image.
I'm trying to use the mini-VGA out put an older style Apple CRT. I get an image but it's all distorted and wavey.
I've connected it to my other eMac (2G) and it works fine.
I cloned it's hard drive and put it into the headless mac, so it should behave the same.
But, it doesn't. I using ReswichX for monitor resolution and when I plug in the monitor to my 2G it works fine, but not with my 1G.
I've even tried swapping 1G boards over for another one I have and again the same image comes up.
You can see the programs and OS running...barely.

Any help or advice would be great.

Thanks

Gav.

JonnZ

Apr 2, 2006, 12:30 PM

Hey Folks,

I run my Headless eMAc(1G 700 Mhz) with a old AT Power supply. The video works on both connectors.
My problem is, that my eMac won't boot anymore with the AT Power supply.
With many different boot CDs(all 10.3) the eMac stops to boot with the grey Display and a strange sign, I found out it's called the "prohibited sign" or formerly broken folder sign.
The boot CDs I used are working fine, I tried them with my old iMac G3, it booted fine off the Cds.

Has any one a clue what the problem could be?

Thanks for your answers.

JonnZ

Apr 2, 2006, 12:39 PM

I've managed to get a 1G mother board and now it is working as a headless mac but I've ran into a problem outputing the image.
I'm trying to use the mini-VGA out put an older style Apple CRT. I get an image but it's all distorted and wavey.
Gav.

Hi Brutus 19,

what you experienced with the Mini-VGA adapter is quite normal. The Video quality on the Mini-VGA output is not as good as the internal one. I compared both images and the Mini-VGa output is a good deal worse in brightness and contrast, no matter how high those settings are.
But the output should not be distorted. Perhaps you should try to use a better CRT. I have a quite new one from LG, and the image is quite ok on the mini-VGa output.
I advice you to solder a normal VGA-Connector to the internal video connector. Its not to difficult, and no problem at all, if you have some experience with the solder iron. There are only 8 wires needed to run a monitor on this internal connector. The image wth this connectos is much better than on the mini-VGa ouptut.
You can also find the pinout for the mentioned connectors in this thread, some pages earlier

cpg

Aug 21, 2006, 02:24 PM

Hallo,
I am happy to find this site and lbodnar's site of the "headless eMac" .
But I don't know - what shall I do - repair the analog-board of my eMac G4 700 or connect it to an atx-power-supply and a TFT-Panel.
Has anyone a shematic of the analog power-board?
Maybe I can find the mistake....
Best regards
CPG

cpg

Oct 25, 2006, 04:29 AM

Hallo,
I was soldering some hours.
I have now atx-power for my emac 700 and the self-made-dcb.
The voltages are ok, but the emac doesn't start.
The cpu is warm - not hot.
The LM317 is not hot - a little little bit warmer than the room-temperature. The voltages are ok.

Any idea?

Best regards
cpg

ffoofighter2001

May 8, 2007, 06:34 PM

Hi all, I know this is a newbie question but I've been searching around for a while and I'm getting frustrated.
There are plenty of sites telling me what things to solder on these emac 800mhz but I'm just not sure how to do it exactly? Some say to bridge certain points on the logic board and some people suggest solder pens etc.
If someone could pm me or help me or point me to a detailed article etc, on how to solder these points to overclock the emac it would be awesome!
Thanks a lot
=Paul=

topgunn

May 11, 2007, 08:42 AM

Basically, all you are looking to do is to complete the circuit. Some people like to use solder pins because they are easy. Personally, however I connect the two pads, I want it to be able to undo it. Solder pins don't let you do that unless you want to scrape the pcb with a razor blade. Some people have reported success with graphite pencil lead. I would not feel comfortable doing that.

I used a tiny blob of solder to complete the circuit. If you mess up or if the clock speed is too high, you can use a variety of methods to remove the solder after the fact. I use desoldering braid for that.

If you have already removed the required jumpers, I wouldn't figure this would be a problem for you.

madmaxmedia

May 11, 2007, 11:50 AM

The original link in the first post has a closeup photo with pads connected with solder-

http://www.lbodnar.dsl.pipex.com/eMac/eMac-upgrade.html
http://www.lbodnar.dsl.pipex.com/eMac/eMac-jumpers-closeup.jpg

As topgunn says, you just need a tiny blob of solder that connects the pads (and obviously doesn't touch other pads, etc.)

I did it the same way. You definitely want to be careful, but it's not that hard. I don't have much experience soldering and I did it, although I do have some experience taking computers apart, etc. Having some sort of magnifying glass or something like that will help you apply the solder, as the pads are pretty small.

Scarecrow84

Aug 22, 2007, 12:20 AM

Hello, I'm looking for Leo Bodnar, the legendary emac know-it-all. I've tried contacting him several times through email and haven't gotten any response. I have some questions about making my Gen 1 eMac headless. If anyone knows how to get a hold of him or if you still come on these forums Leo, please let me know! I could really use your help right now...

geekmaster64

Nov 8, 2007, 06:48 PM

Hello everyone. I was doing some research to overclock my Gen 3 1.25GHz eMac and it worked. I Have it running @ 1.58GHz for the last 2 months now. Only locked up once and that was when it was 88 in the basement.

My only problem is the bug that the firmware has when it is at 1.58GHz. ATM shows only 750MHz. Which sucks because the link to a website forum that had a fix is gone. If anyone knows how to fix that it would be unreal.

Brandon

KingYaba

Nov 9, 2007, 12:33 PM

Hello everyone. I was doing some research to overclock my Gen 3 1.25GHz eMac and it worked. I Have it running @ 1.58GHz for the last 2 months now.

Please share that research.

geekmaster64

Nov 9, 2007, 06:43 PM

Great! Here they are then:

1.25 1.33 1.42 1.50 1.58 1.67 1.75GHz
R658 (reverse side) + - + + + - -
R270 (J11 side) + - - - - + +
R673 (reverse side) + + - - - - +
R275 (J11 side) - + + - - + +
R689 (reverse side) + + + - + - -
As usual, "+" means either resistor or solder bridge is present and "-" is an open contact or removed resistor.

Just to let you know, Open Firmware might not correctly show 1.58GHz speed (displayed as 750MHz) because no Mac yet runs at that speed. This issue is the same on Mac mini - it has the same CPU and very similar architecture. It is purely indication issue and the solution can be found here (http://macminiforums.com/forums/showpost.php?p=2205&postcount=107)

I just used that Key above from page 16. The only problem is that part about the firmware reading 750MHz. Seems that there was a website with a fix but that website is gone. :(

gripnrip

Jan 13, 2008, 11:53 PM

Instructions for a Mac Mini but I suppose it will work for an emac. (Haven't tried it). I overclocked my 1.25Ghz emac to 1.42 or 1.5, but it reads 417 MHz in "About this Mac". Still trying to figure that out... from:
http://www.123macmini.com/forums/viewtopic.php?t=15109&view=previous&sid=45bb3b3b5bc2238bc264381e240a15c0

These are the values for 1.58GHz overclock:
1.58 GHz PowerPC G4
5e2ce2fd = 1579999997 = " clock frequency"
5e1da0c0 = 1579000000 = " rounded-clock-frequency"
5e178682 = 1578600066 = " recalced-clock-frequency"

Here's the instructions on how to persist the 1.58GHz into the system so that "About This Mac" works properly:
1. Reboot the computer holding down Cmd-Opt-O-F to enter the Open Firmware command line.
2. Type nvedit and press Return
3. Enter the following script exactly, pressing Return at the end of each line.
Code:
dev /
9eb18ef encode-int " clock-frequency" property
dev /cpus
dev PowerPC,G4@0
5e2ce2fd encode-int " clock-frequency" property
9eb18ef encode-int " bus-frequency" property
5e1da0c0 encode-int " rounded-clock-frequency" property
5e178682 encode-int " recalced-clock-frequency" property
27ac63b encode-int " timebase-frequency" property
dev l2-cache
5e2ce2fd encode-int " clock-frequency" property
dev /
4. Press Ctrl-C to exit the editor.
5. Type nvstore and press Return
6. Type setenv use-nvramrc? true and then press Return
7. Type reset-all and press Return

Markus1077

Feb 2, 2008, 01:07 AM

Hi everyone, i'm new to the whole "cutting up my apple" deal... i'm trying to work on my 700mHz gen1 G4 emac

i'm trying to make it work headless, with a twist... i want to get the internals into a mac plus case that i've got lying around

i've seen all the advice on how to make it work "headless" but i still have some questions.

1) can i make my emac work through an ATX power supply and completely remove the analogue board? if so... how?

2) i swear i had another question, but thats the big one at the moment!

i'd love it if someone can help me out with this!

cheers,
:apple: Mark :apple:

DesScorp

Feb 14, 2008, 05:12 PM

Has anyone else done the same mod to the eMac 800 mhz model that lbodnar has? I've got one, and I'd like to try it, but I have a couple of questions...

First, I've never soldered anything, but I've purchased a "teach soldering" kit that lets you practice making simple things like flashing lights and AM radios. I don't want my eMac motherboard to be my first attempt...

After that's out of the way, I'll give the up-clocking mod a try. I've been to lbodnar's page on the subject, seen the photos and the tables....all very helpful. However, here are my questions:

I've downloaded the pics of the jumper area of the motherboard, and magnified it some to have a better look. I also looked at the tables provided, and if I'm reading the page correctly, he's simply stating that all that's involved here is removing resistors from R1512 and R1518 (via a soldering iron), and then using spare solder to create bridges on R1509 and then R1515? That's it?

Another question....on the table, R1518 is listed as one of the resistors with a jumper, and yet on the motherboard grid itself, the picture seems to indicate that the resistor in question is R1517...it's the next number in sequence, right next to R1515 on the motherboard printed grid. Perhaps I'm missing something here, or perhaps I'm reading the grid wrong. Suggestions? Folks? I don't want to screw this up.

Here's lbodnar's original pic of the modified board:

http://i123.photobucket.com/albums/o306/DesScorp/eMac-jumpers-closeup.jpg?t=1203026858

Here's my version, with questions....

http://i123.photobucket.com/albums/o306/DesScorp/eMac-jumpers-questions.jpg?t=1203026935

Also, does it appear that R1506 has also been removed?

geekmaster64

Apr 3, 2008, 09:40 PM

ease718

Apr 4, 2008, 11:35 AM

you guys should really check out some of the OSx86 stuff you can find on google, lol

geekmaster64

Apr 4, 2008, 01:27 PM

you guys should really check out some of the OSx86 stuff you can find on google, lol

Now why would we wanna do that?

ease718

Apr 4, 2008, 01:40 PM

Now why would we wanna do that?

a. check my benchmarks for starters :-)

b runs absolutely everything my real mac does ( actually some things much better lol).

dont get me wrong i oc'ed a mac se20 then centris, quadra's etc back in the day, and i think this a great thread

geekmaster64

Apr 6, 2008, 12:23 AM

a. check my benchmarks for starters :-)

b runs absolutely everything my real mac does ( actually some things much better lol).

dont get me wrong i oc'ed a mac se20 then centris, quadra's etc back in the day, and i think this a great thread

But afterall,

Its still not a Mac. Only pretending :P

madmaxmedia

Apr 6, 2008, 02:34 AM

I installed Tiger on a Centrino notebook a year or so back, it ran pretty good considering it didn't have SSE2.

I'd love to find a really cheap P4 (around 3 Ghz) that supports SSE3 and install Leopard on it, and see how it compares with my 1.25 Ghz eMac.

a. check my benchmarks for starters :-)

b runs absolutely everything my real mac does ( actually some things much better lol).

dont get me wrong i oc'ed a mac se20 then centris, quadra's etc back in the day, and i think this a great thread

ease718

Apr 6, 2008, 11:38 AM

you can get a motherboard for about $80, a E2180 dual core 2.0GHz (oc'ed to3.0) for $80 and $80 for 2GB 800ddr ram. also < $80 for a 7300GT graphics card.

my machine is a speed monster. I spent a total of $700.
4gb of RAM from apple is $700. as is a mac mini.

the satisfaction of rolling your own .. priceless.

i openly challenge any mac pro quad to ANY speed test :-)

it may not be a 'real' mac but that only makes the experience sweeter.
It runs a 'vanilla' stock kernal and for all intents and purposes Leopard the real deal.

i am so tried of the apple desktop lineup being either reboxed laptops or server workstations rebranded as desktops sold for crazy prices.
the mac pro desktops are stupidly expensive for performance that could be had at a reasonable price. there really is a place for a modern day emac built from desktop parts.