Mod G4 iMac with Intel Mac mini innards?

[casesensitive]

Hi all,

first post, and it's a biggie..
I have a 20" Luxo/iLamp G4 iMac that I love to pieces, far and away the most beautiful thing I've ever owned, and I've given her everything she's ever wanted, 1.5Gb of RAM, 2x300 Gb HDDs, 16XDL DVD+-RW, the works. However, compressing video is a horrible chore, Civ IV is a no-go, and my little Sony S1 Windoze laptop humiliates Luxo in every operation.

The Daystar 1.92Ghz G4 looks like the only option for me, but for what will end up costing over $600 I'll get about 20-40% more CPU grunt, not much of a return.

I've been inside her many times, and it strikes me that the Mac Mini motherboard would fit comfortably in the case, and I've been looking lustily at Meromini Macs that a few folks have put together.
The trouble is, despite getting the service manuals etc, I'm at a loss as to how I can get my iMac's gorgeous screen to take a VGA/DVI input. The power issue I could get around.

Any ideas? Anyone know of anyone who's tried anything similar?

[cbetta]

I recently bought a iMac G4 (as an art piece for nexto my macbook) and I love it. I have taken it apart and upgraded some parts (harddisk, memory, airport), but it still lacks some speed for some things I do on my macbook. I would really like to know if anyone is able to fit a mac mini in it's casing. It should fit because a mac mini has laptop hardware while a iMac G4 does NOT.

Can I ask what DVD-RW you bought to fit in the iMac G4 as superdrive?

[casesensitive]

Internal spec:

Airport and Bluetooth
Dimm 0 (J22) 512Mb PC2700 RAM
Dimm 1 (J20) 1024Mb PC2700 RAM (both from Crucial.com)
300Gb Maxtor ATA133 6L300R0
300Gb Maxtor OneTouch II FW (incidentally, the exact same disk!)
Pioneer DVR-109, pre-flashed I think (from xlr8yourmac.com shop)

On all occassions, I had no trouble selling on the removed Apple-shipped parts to either PC or Mac owners.
Yeah, I'm pysched by the idea, I've gone in on 4 seperate occassions (2xHDD replacement, 1xinternal DIMM, 1xSuperdrive).

I bought a Pioneer DVR-109, which in Panther needed Patchburn3 to work with iApps, but since I moved to Tiger, I haven't bothered, and I burn in Toast all the time. That said, I haven't installed iLife again yet.

[wPod]

cool idea! i have fallen in love with my mac mini and modding mac minis :-) i think it would be awsome to see a mini in an iMac G4 shell!

check out this thread (http://forums.macrumors.com/showthread.php?t=224481) to see what ive done to my mini. maybe one day if we get enough interest we could have a mod catagory!

. . . if anyone wants to send me an iMac G4 shell, then id be interested in giving it a go!!

[cbetta]

is it me or dont i see any shop at that site? im from europe so that could be a problem

[casesensitive]

Yeah, I'm going to try and pick up a broken/sick 15" Luxo to play with first, at least until I figure out the display connector and psu issues. Then into my 20"er..

Xlr8yourmac.com are US-based, and ship to Europe, but their shop partner is called Other World Computing on http://eshop.macsales.com, and they sell guaranteed-to-work drives for any given computer. That said, there's no reason why you shouldn't just buy a Pioneer DVR-109 from newegg or similar, as I've taken the risk out of it by using one successfully. The only tricky part is the removal of the bezel, otherwise the xlr8yourmac G4 take-apart is pretty accurate.

Beware though, after multiple openings of the case, I ran the thread on one of the sprung-screws holding the aluminium base shielding on, and I had to drill it out!

Google will have to get me through this one I think..

[casesensitive]

I'm going to try and pick up an iMac G4 with a working screen and fried board, hopefully the 21-pin connector will prove to be a re-worked VGA lead (it's reasonable to assume, it uses standard Nvidia gfx chipsets and the external connector is VGA). Even a funky ADC lead would not be an insurmountable problem.

Is anyone out there half-way qualified to help with this? I did most of an electronic engineering degree before switching to computer science, but it's been 7 years since I soldered at work.

Anyone want to donate/sell very cheaply a fried iMac? Or even just the display?

If I do figure it all out, I'll take loads of pictures and write up a full how-to. Any help much appreciated!

Updates:
The TDMS cable referred to in the Apple docs defintitely a digital signal cable, which means it's some sort of DVI connector (or ADC, which is essentially DVI).
ADC pinout: http://www.interfacebus.com/Apple_Video_Bus_PinOut.html
Display connectors: http://www.devhardware.com/forums/computer-monitors-79/the-ultimate-video-connector-guide-98686.html

[cbetta]

Nice work on the researc. Your entire story got me thinking about something else: mounting a 20" screen on a 15" base. I have the option of buying a cheap 20" screen, but I wonder if it is possible to be fitted on a 15" base, do you have any idea on this?

[casesensitive]

Interesting idea alright.. I know the arm in the 20" one is way stronger, and the base is heavier to account for the extra weight of the 20" screen, so if you did get the 20" screen attached, you'd have to add 'balast' to your base to stop it falling over!
Also, the Geforce 2MXs in the first and second revisions (700/800Mhz) are only capable of outputting 1024x768 even to external monitors.
http://developer.apple.com/documentation/Hardware/Developer_Notes/Macintosh_CPUs-G4/iMac_012202/2_Architecture/iVideo_Display_Subsystem_.html
Which would look yuck on a 20" widescreen monitor..

Sounds like a bit of a downer on that one really.
I've been reading a fair bit about the ICs that drive the 20", which are on the logic board and not in the monitor and it looks like if I do get it working, it'll only be at the native resolution, which probably means no games :-(

[pmackin]

the sony dru-810a and 820 work fine on the flat panel imac.. just plug them in an you are ready to go.

[pmackin]

These might help .. i cudnt find the 20inch manual but this one shud do the trick.
http://rapidshare.de/files/29488806/imac_17in_1ghz.pdf.html

[casesensitive]

Yeah, I actually bought a CD from EBay with all of those service manuals for every Mac 'puter ever made (with free updates, but naturally, I lost the ftp details), including my 20".

Unfortunately, the only teach a repair monkey how to *replace* parts, not fix/mod them, so beyond describing them as a TDMS connector and power inverter respectively, it's not very educational..

I think 'black-box'ing another corpse is the only way I'm going to get the info I need :-(

[Jovian9]

This is something that would be great to see done as my favorite Mac of all time is the iMac G4 (I've owned 2 but no longer have them). Though I'd really love it if someone figured out how to completely gut it and put the innards of a MacMini Intel in it. Then I would probably buy one and have that done or do it myself :)

[sunfast]

I have an iMac G4 and would love to make it gorgeous on the inside too. Sadly it doesn't get a look in these days as my MB just embarasses it.

[furious]

the only problem i would foresee is the monitor and its connection to the mini logic board

everything else should be a sure thing :confused: maybe USB issues but you could make a walk-around in the form of a USB Hub

[ericarthur]

I've been thinking of doing the same thing for some time with my 15" 800Mhz G4. Have you had any luck on the video front? I've had a look around inside and can't see any other problems with the upgrade - has anyone else spotted any?

[casesensitive]

Not really, the building of an interface between a DVI output and the quirky internal arrangement of my iMac has defeated me thus far. That, and the arrival of C2D 24" iMacs didn't help, I'm close to buying one..
If I could pick up a cheap Mini solo, and a dead iMac (even 15"), I'd get going, but for now, my iLamp is frustrating me with it's lack of oomph (4.5 hours to rip a DVD to FFMpeg in Handbrake). I may just make it a secondary PC when the new baby arrives :-(

[kgarchar]

I'm kindof looking for the exact opposite. I want an iMac G4 with a broken screen so i can use the VGA out and get maybe a 19 in widescreen monitor and possibly mount that on the display thing. Let me know if anyone has a 1GHz or more G4 with a messed up screen. I'd be willing to buy it.

[nickelbackmac]

So, you're putting the Mini in an iMac G4 case?

Maybe when I get my next Mini I'll do that.

But 1 question: How will the Combo/Superdrive work? If you're putting the Mini inside the shell, are you going to cut a hole for the optical drive, or somehow use the tray-load on the iMac?

[cbetta]

hmm, that is a good question. can't the iMac superdrive just work instead of the mac mini drive?

[acmeaudioeng]

mac mini's with the Intel CPU are serial ATA, the older imacs (g4) are ide/ata, I'm thinking there might be a small issue, but not possitive... I havn't tried anything like that (cross breeding my PPC's and Macintels)... some one shoot me the details if they get the bugs sorted out... dying to do the same with my G4 imac and a mew mini.

[Modjo]

Now this is a thread i hope will stay alive.
I own a 15" G4 iMac 800 and i'll never ever get rid of it. It's just too beautifull and nifty.
I've upgraded it to the max RAM etc, ... but is starting to become obsolete.

I'm no electrician or engineer, but i'm quite handy with things like this. So if anyone succeeds in pulling this off, please explain how it's done!

I don't have the skills to figure it out myself, and it's still my main computer so i can't mess around with it.

How sweet would it be to put a (soon te arrive) C2D with some 3gs RAM etc. in a design like that!

btw: those ide to sata adapters allready exist. They aren't too big, but size isn't something there's plenty of in an iMac.
The combo/superdive shouldn't be a problem, if i have to i'll remove the mechanism so the "door" will just fall open if something pushes against it at the back, i'm willing to do so.

[MatthewCobb]

Now this is a thread i hope will stay alive.


Me too. Still have and love my G4 anglepoise (see sig), but, as with many other posters, would like for-the-rest-of-us outline for how to mod it. The most I've done on any Mac is replacing RAM, superdrive and keyboard (easy-peasy). I think this sounds complicated!

[cbetta]

I think the real bottleneck here is finding a proper way of connecting the iMac screen to the mini mainboard. If someone can figure this out, I can make a noobs-tutorial for the rest :D

[Poff]

There was a thread on this a little while ago. Should be on page 1-2-3, I guess. I believe you'll have to get a new screen, since you'll probably have a problem communicating with the screen allready in the G4.

I have a 15" imac, and a 1600x1200 screen in there, together with a mac mini, would be great! :cool: :D

Edit: see this (http://forums.macrumors.com/showthread.php?t=237409) thread.

[reinchic]

I too love my 15'' 1Ghz imac and was wondering about the possibility of putting a 17'' screen on it in the future. I was going to sell it to help pay for a MBP, but alas, it is too beautiful and everything is so square and boring now. I'm not an engineer by any means, but my family members are, so if anyone out there thinks it would be feasible, I'll start hunting for screens and instructions!!

[cbetta]

im sad to say I just sold my old iMac 15" for a Mac Mini. Mainly because my iMac didnt have any USB2, and was to big to bring with me when I move to London.

[pmackin]

I've looking at the manuals .. on the flat panel imac the lcd connects to a inver ter .. which connects to the lcd .
now my question is , could there be a way to get a cable from the dvi port of the mini and run it to the inverter ?
forget about routing the cable for now , but will this work electrically speaking.

[ericarthur]

does anyone have the service manual for the iMac 15"? I saw it once and there was a wiring guide for the video wire. That would make a DVI adaptor much easier.

[Stadsport]

I've looking at the manuals .. on the flat panel imac the lcd connects to a inver ter .. which connects to the lcd .
now my question is , could there be a way to get a cable from the dvi port of the mini and run it to the inverter ?
forget about routing the cable for now , but will this work electrically speaking.

The inverter is to power the flourescent lamp (backlight). DVI is the signal.

[Sam0r]

Forget about power for now, thats a 10 second job, especially since the inverter is already in the display. It'll just need DC power (Probably 12v) and the correct DVI signal.

You say there are 12 pins?

Can I get a picture of the connector?

[GrimmMac]

Forget about power for now, thats a 10 second job, especially since the inverter is already in the display. It'll just need DC power (Probably 12v) and the correct DVI signal.

You say there are 12 pins?

Can I get a picture of the connector?

Well, something died inside of my 17" iLamp G4. When you push the power button absolutely nothing happens. A few hours later and I've got the thing completely dismantled and found this thread via google :)

I am hoping to be able to use the LCD as the primay display for my wife's G5 tower or a secondary monitor on my MacPro tower.

I have taken several photos of the connectors in question and hopefully someone a little more savvy than me can help us all solve the problem of driving one of these things with a VGA or DVI output from a computer.

I will see about posting those photos...

[GrimmMac]

There are four main cables that exit the metal support arm. They are clearly in pairs, two apparently dealing with power. These two cables come from the motherboard via a 16 pin connector out to the fan, speaker and then into the LCD as well. One of the wires is clearly labeled "INVERTER CABLE"

The other pair is what I believe to be the video signal heading into the LCD. One cable is light gray, the other black. They come out of the support arm separatley but then terminate in a single connector which was attached to the motherboard.

It has 21 pins in two rows. One row with 11 the other with 10. The two cables are taped together with a label which reads 620-2305. The connector itself has the word "Foxconn" stamped into it on both sides. The metal bracket on the connector is just over 5/8" wide; the 11 pin side is 9/16"; the 10 pin side is 1/2". I hope this is helpful to someone :)

66989

[Sam0r]

There are four main cables that exit the metal support arm. They are clearly in pairs, two apparently dealing with power. These two cables come from the motherboard via a 16 pin connector out to the fan, speaker and then into the LCD as well. One of the wires is clearly labeled "INVERTER CABLE"

The other pair is what I believe to be the video signal heading into the LCD. One cable is light gray, the other black. They come out of the support arm separatley but then terminate in a single connector which was attached to the motherboard.

It has 21 pins in two rows. One row with 11 the other with 10. The two cables are taped together with a label which reads 620-2305. The connector itself has the word "Foxconn" stamped into it on both sides. The metal bracket on the connector is just over 5/8" wide; the 11 pin side is 9/16"; the 10 pin side is 1/2". I hope this is helpful to someone :)



Thats going to be VGA/DVI then. It'll be DVI though.

Any pictures of the wires coming out of that connection? I need the colours of the wires, each individual wire that is. All 21.

[GrimmMac]

If you want to see what the wires for each of the 21 pins look like, I have three choices:

1) Hack the two cables in half to expose the individual wires within each.

2) Attempt to expose the wires coming out of that connector by removing the plastic jacket near the connector itself.

3) Disassemble the LCD enclosure to see if the wires might be exposed on the other end.

I'm not particularly fond of 1, but that is surely the easiest way to do it.
Option 2 is likely to be the most reversible of the three options, but may or may not work.
Opening up the LCD enclosure is a gamble on whether the wires are even exposed.

[Sam0r]

Option 2 would be fine.

Although if you want to fit the LCD to a Mini, you'll have to hack apart the cable anyway, although I don't know if thats your intention or not.

[GrimmMac]

My particular intent is to attempt to attach it to the DVI port on my PowerMac G5 or else MacPro Tower. I will have to take pictures and post them tomorrow. I should have been in bed 3 hours ago :D

[fuyutsuki]

I have a busted 800MHz Superdrive 15" iMac G4 I picked up for free recently and can verify what's just been said about the wiring. (Mine is DOA so I suspect the power supply and/or motherboard.)

The crucial connector is the silver coloured one photographed above, which is actually quite small and has 21 pins, clipping into its mate on the motherboard with a satisfying 'click'. There is also the second cable talked about which seems to be for power to the LCD and other devices along the way.

Now I also happen to have the service manual, and have just been Googling for data. Here's some of what I've come up with:

The Geforce 2 graphics card does all the video scaling by itself, supporting fullscreen stretched resolutions at:

640x480 @ 60Hz
800x600 @ 75Hz
1024x768 @ 75Hz

The secondary output is a Mini VGA plug (14 pin) and supports mirror mode only, unless you use a firmware patch.


I don't know much about internal connections to digital displays, but which is more likely: this crucial 21 pin connector is VGA based like the secondary output or is something exotic linked to this specific screen?

As said by Stadsport on the other thread:
I had this idea a while ago, and after doing some research I found that not only does the iMac G4 use a wonky connector for the screen, but I'm pretty sure the LCD has no onboard image processor. The iMac's logic board handles the picture.

Damn! Sounds like it may be a better idea to remove the LCD and replace it with an identical sized (and maybe higher res) new one whose inputs are known.

Anyway, since I've been elbow deep inside my broken iMac several times I'd like to add the following notes:


The iMac uses a full size parallel ATA hard drive and optical drive, which are master and slave on its single IDE channel.
The hard drive and power supply share space right at the top of the dome, closest to the neck.
Fitting a Mac Mini inside is quite possible on first glance, but NO WAY with a full size optical drive at the same time, however a 3.5" hard drive is probably fine.
Inside the iMac case is a metal structure called the Faraday Cage which basically makes for a thicker shell, reducing the space from what you'd think
The drive slot at the front is very easily made to open, so you don't need a perfect match to make it work, however a slot drive would need to be "helped" whenever you want to open the door without a disc already in the machine!
Intel Mac Mini's have a large power supply brick which takes the same plug as the iMac but is too big to fit inside the case as well as a Mini, so an external cord trick would need to be used.


Anyway, keep this project alive as I know there are many Sunflower Mac lovers out there, including latecomers like me, who want Intel power in a design classic case. May the hack be with you!

[tuc]

This is pure speculation, but I would expect the signals between the iMac G4 mainboard and its LCD display are pretty much the same as the signals between a powerbook's mainboard and its LCD display.

Why would they bother putting DVI (or VGA) decoding circuitry on the LCD end of the arm if they didn't need to?

[fuyutsuki]

This is pure speculation, but I would expect the signals between the iMac G4 mainboard and its LCD display are pretty much the same as the signals between a powerbook's mainboard and its LCD display.

Why would they bother putting DVI (or VGA) decoding circuitry on the LCD end of the arm if they didn't need to?

This sounds reasonable, so what's it like in the laptops then? Is there some sort of standard that raw data to TFT's is sent in? Is it something we could emulate?

My feeling is that if it's not easily done, it might be best to get hold of an equally sized standalone display (with DVI / VGA connector) and hack that into the Mac instead .. as the iMac's TFT is indeed removable with a little care. Whatever else goes in would need to match the iMac head quite nicely. But then again, it could also be of a higher pixel resolution than the iMac's lowly res. Interesting idea if it's do-able. Especially as a normal screen power supply should be able to fit inside the iMac base quite easily so long as it's not humongous ... especially if we're talking about turning the iMac into a display rather than a display with a Man Mini included in the package!

[GrimmMac]

Here is a shot of all the cables coming from the metal support arm.
http://att.macrumors.com/attachment.php?attachmentid=67306&stc=1&d=1170350345

This is a picture of the exposed wires as they go into the connector. The colors are not completely true to life due to the lighting. The colors are as follows from top to bottom:
(Small wires) Yellow, Green, Blue, Purple, Red, Black, White, Gray, Orange
(Large Wires) Green, Red, Brown, Blue
http://att.macrumors.com/attachment.php?attachmentid=67307&stc=1&d=1170350345

[fuyutsuki]

Nice work. We'll have to see if anyone can tell us what they mean!

[fuyutsuki]

Hmm.... this is the most detailed snip from another thread:

It's probably FPD-Link (http://en.wikipedia.org/wiki/FPD-Link) or maybe, but unlikely LDI (http://en.wikipedia.org/wiki/LDI). These are LDVS signalling technologies often used to connect flatpanel displays to graphics chips. The first is normal in laptops and probably the iMac too.

The Wikipedia turfs this up under LDVS...

http://www.national.com/nationaledge/may01/lvds.html
http://www.national.com/nationaledge/may01/images/lvds_1.gif

I'm thinking ... ¿ay que lastima?

[xyian]

I really hope you all keep this project going strong!
I'm sorry I can't contribute to the cause here but I haven't
done any soldering since high school.
If you do get it up and running though, I will strongly consider
buying an old 20" iMac and attempting this(after much solder
practice, of course....)
Cheers!

[fuyutsuki]

Is it just me, or do the "18+3" wires going into the "TCON" on that diagram above sound a lot like the 21 pins on the video jack? ;)

There's also an 18+3 arrangement on the other side of the picture, right into the VGA (graphics card, which we know is on the iMac motherboard), but that side needs a separate clock signal.

In other news, no luck picking up a generic 15" TFT here to pursue the alternative.

[R0ck1t]

I also own the iMac G4 (But 17" as no one seems to on this thread), I have opened it and had a look but have limited knowledge of computer functions.
I'll soon have Electronics & I.T GCSEs and would gladly help if anyone can think of a way I can.
P.S
If anyone knows of a way to upgrade the USB1.1 to USB2 or have an external hub I would be grateful if you shared this wisdom.
Cheers.

[gramorris]

I've got a 17in which I can't bring myself to dump yet and I've been furiously researching hooking up a mini to the display. This thread seems like the best hope so far although I can't say I have any experience doing this but I will help if I can.

[dukeman]

You need a controller between the LCD and the Mini VGA out. There is no way to directly connect the wires from the LCD to the Mini. The imac has this "controller" built into the logic board, as do most laptops. You can buy a controller "http://store.earthlcd.com/LCD-Products/Analog-VGA-Controller-Cards"
but they can get pricey. Second option might be to take apart a stand alone LCD monitor and borrow some parts, just watch the power outputs / inputs, would be easy to fry your good LCD Panel.

[fuyutsuki]

You need a controller between the LCD and the Mini VGA out. There is no way to directly connect the wires from the LCD to the Mini. The imac has this "controller" built into the logic board, as do most laptops. You can buy a controller "http://store.earthlcd.com/LCD-Products/Analog-VGA-Controller-Cards" (http://store.earthlcd.com/LCD-Products/Analog-VGA-Controller-Cards)
but they can get pricey. Second option might be to take apart a stand alone LCD monitor and borrow some parts, just watch the power outputs / inputs, would be easy to fry your good LCD Panel.

Nice link. This looks promising:

NK-GM2221-421 LCD Controller KIt

MultiMedia LCD Controller Kit
(includes everything but the LCD)

Call for LCD Compatability

Could someone in the US give them a call? As in ask if they know the iMac G4 and whether it's 15, 17 or 20" TFT is compatible with their board. I don't fancy crossing the Atlantic with my phone company, this is what the internet's for after all! ;)

[Maxwell Smart]

This discussion looks promising. An intel mini inside an iMac G4 would be so cool, not only because of the obvious increase in performance and new RAM ceiling (of 3GB) but also because you could probably get a full size 3.5" hard drive inside, and can easily upgrade the mini's processor because it's socketed. Good Luck with this, unfortunately I don't have an iMac G4 otherwise I would try to contribute.

[dukeman]

Send them an email with the whitepages for the imac lcd in question and they will tell you. I havent had time to hunt down the whitepages but got an email back asking for them about an hour after i emailed sales.

[tuc]

Originally Posted (http://forums.macrumors.com/showthread.php?p=2529993#post2529993) by robbieduncan:
It's probably FPD-Link or maybe, but unlikely LDI. These are LDVS signalling technologies often used to connect flatpanel displays to graphics chips. The first is normal in laptops and probably the iMac too.


From what I can tell (and I know nothing) it probably does use LDVS (FPD-Link/LDI), but it could possibly use TMDS (DVI/HMDI/???). Some graphics chips have built-in TMDS senders, so I suppose Apple could have used it in the g4 imac if they had wanted to for some reason.

Even if we somehow determine it uses FPD-Link, there are 18-, 24-, and 48-bit senders and receivers. I would guess that Apple would use 24-bit, but what do I know? I guess we could look at the markings on the chips and see if there is anything to be discovered. For example, if we see a chip marked DS90CF384A (http://www.national.com/pf/DS/DS90CF384A.html) on the display end of the arm, then we know it's 24-bit LVDI. (Though I guess it is possible (http://www.national.com/an/AN/AN-1127.pdf) that the sender was 18-bit instead.)

The thing is, there are sure to be people out there who know exactly what the g4 imac (and other iMac/eMac models) uses, if we could only find them.

[The Senator]

why not just rip everything out of an intel imac and put in all in the imac g4?

[ezekielrage_99]

That sounds pretty cool, I was thinking about doing the same to my G4 Graphite iMac. I haven't found much info on the net about doing that so that has been a deterant to me.

[fuyutsuki]

why not just rip everything out of an intel imac and put in all in the imac g4?

We have considered that. You'd need to put in a different display though as well, as this whole thread has basically come down to the tricky "how to send video to the iMac's original TFT?" question.

[fuyutsuki]

That sounds pretty cool, I was thinking about doing the same to my G4 Graphite iMac. I haven't found much info on the net about doing that so that has been a deterant to me.

Graphite G4 iMac? I think you mean G3. Doing it to one of those is also a possibility. But the same problem arises of how to use the screen. Mind, I have seen an original Macintosh used for a Mac Mini housing so maybe CRT's are easier:

http://www.destruc.tv/minitosh.php

[ezekielrage_99]

Graphite G4 iMac? I think you mean G3. Doing it to one of those is also a possibility. But the same problem arises of how to use the screen. Mind, I have seen an original Macintosh used for a Mac Mini housing so maybe CRT's are easier:

http://www.destruc.tv/minitosh.php

woops I meant G3, thanks for the link.

[Blixten]

First of all: Hi!
I followed this thread for quite some time now, as I have a broken 17" iMac waiting for the Mini :).
From what I can tell (and I know nothing) it probably does use LDVS (FPD-Link/LDI), but it could possibly use TMDS (DVI/HMDI/???). Some graphics chips have built-in TMDS senders, so I suppose Apple could have used it in the g4 imac if they had wanted to for some reason.

It does use TMDS (at least there are "TMDS cables" mentioned in the service manual). As DVI is based on TMDS, a direct connection could be possible.
Recently, even the pin layout of the screen connector has been posted, here (http://www.applefritter.com/node/18351).
I'll wait for the next generation of Minis with C2D and try that out.

But there is one more question: If you look inside the G4, you see the 3.5" optical drive placed right in the middle of the mac (where the door is of course). There is hardly enough space for a Mini above the drive and it's definately too narrow below, so I thought about removing the power-supply.
Or do you have any other ideas (like motor-driven slim drives etc)?

[fuyutsuki]

It does use TMDS (at least there are "TMDS cables" mentioned in the service manual). As DVI is based on TMDS, a direct connection could be possible.
Recently, even the pin layout of the screen connector has been posted, here (http://www.applefritter.com/node/18351).
I'll wait for the next generation of Minis with C2D and try that out.


Nice work spotting that. Hopefully someone knows what they're doing!


But there is one more question: If you look inside the G4, you see the 3.5" optical drive placed right in the middle of the mac (where the door is of course). There is hardly enough space for a Mini above the drive and it's definately too narrow below, so I thought about removing the power-supply.
Or do you have any other ideas (like motor-driven slim drives etc)?


Yeah, I've written about this before. Here's the dirt:


The iMac's optical drive is indeed totally in the way of putting in an entire Mac Mini, because it is right in the middle dominating the case
Those old drives aren't so hot anyway (I know, easily replaceable of course!)
The entire iMac "dome" is smaller than it seems from the outside because of a metal lining Apple calls the Faraday Cage (electric shielding), it's actually not at all big inside
With a Mac Mini inside, you won't need the iMac power supply so that could clear up a lot of space "up top", removing the fan which lies up there too
The external door for the optical drive is easy to push open, it's not very fussy so there's scope for inventive hacking there!


Now these are the things to note about an Intel Mac Mini:


Again, the optical drive dominates the insides. If you open a Mini and take off the drive, it's surprisingly small!
The Mini cools itself very well and extremely quietly, I reckon so long as the air holes remain clear at the top of the iMac case it should be more or less fine, especially if its in contact with the Faraday Cage which was a trick the iMac's mobo used too with a metal conductive cooling pipe
The other bulky thing about a Mini is its external power brick, which I reckon is probably something you need to keep outside the iMac


So what I mean is that the iMac is a bit tight inside, but a Mini really is a tiny computer when you take its lid and disc drive off. Just looking at my two machines makes me think you could actually put a Mini in the space *under* the iMac optical drive (replaced with a nice 16x superdrive naturally). But I can't be sure without opening up my Mini which is currently letting me write this!

Another option is like you said, using a slim burner and lining it up for the door. Using a (sweet) slot loader like the Mini's wouldn't work, but a tray loader shouldn't be a big problem so long as you can mount it nice and solid. Does anyone still use tray loading laptop drives? I don't know what's available but I wouldn't be surprised if there's some good choice out there. Note: the tray needs to be tough enough to survive in this new environment with a door to push against, so it can't be too delicate.

The easiest of all options is to ditch optical drives entirely and make a network centric All in One Mac. Even if all you could plug into the thing was power and optionally usb for non-bluetooth mouse+kb, I'd consider it a useful computer alongside others. The fact all Intel Mac Minis come with built in wi-fi is handy too.

One more thing: ports. The iMac has its ports in a curve around its base. This could make routing them to the Mini a little difficult. The actual ports are on the motherboard anyway, which needs to be removed so you basically have to furnish your own. A cheapskate solution would be to leave the holes and just thread your favourite leads right into to the internal Mac Mini before screwing on the base (thankfully an easy procedure!). But of course it'd be much nicer to use little extenders and have real ports available.

I still think the screen issue is the main problem to be resolved. It's good to see progress on it, but I'm only going to believe it when I see a positive report.

[Locatel]

This is an intereting project guys!!! Don't led the thread die!!! I would be happy just to connect the Mac mini to the iMac LCD, it doesn't have to fit inside the case, I would live with it sitting nearby, just like an external HD...
Please post any progress!!!

[Locatel]

This is an intereting project guys!!! Don't led the thread die!!! I would be happy just to connect the Mac mini to the iMac LCD, it doesn't have to fit inside the case, I would live with it sitting nearby, just like an external HD...
Please post any progress!!!

[fuyutsuki]

As far as I remember, we were stuck on the connector and just what circuitry is present or absent at the LCD end…

[porcustal]

well atm I have an imac g4 15" sitting on a table all taken apart :) with the intent to use it as an external monitor and HD. I'm waiting for a few parts and to figure out the other cables, cause i'm a little iffy about the inverter wires

but what i intend to do is, if i got all my info correct, cut the TMDS connector off the cable and using a few of the other screen wires and the info from here http://www.applefritter.com/node/18351 put them all into a female DVI connector. Then i'll cut out a DVI sized hole in the back body and be able to connect to it externaly...

The imac which still works kinda will still have the mini-vga, but i'm not sure whether i'll keep the innards intact or just use it as a housing, how i want power the screen will probably decide. first though i need to replace the screen inverter :rolleyes: .

[fuyutsuki]

Good luck.

I'd love to hear a tale of success, as my own more completely broken iMac G4 is still lying sadly still and in need of an awesome mod.

[theycallmepost]

I just finished reading through this thread and had an idea..

It seems that no one has reached a conclusion on whether or not the panel uses FPD-Link/LDI or TMDS, but there are Mini-ITX form factor motherboards with built in LVDS connectors..

Surely the panel can be attached and this will clear up some confusion?

And to play devil's advocate.... if it works, a lot of time could be saved if a PC ::shudder:: was just put in the base.

[fuyutsuki]

I just finished reading through this thread and had an idea..

It seems that no one has reached a conclusion on whether or not the panel uses FPD-Link/LDI or TMDS, but there are Mini-ITX form factor motherboards with built in LVDS connectors..

Surely the panel can be attached and this will clear up some confusion?

And to play devil's advocate.... if it works, a lot of time could be saved if a PC ::shudder:: was just put in the base.

Perhaps, just for an experiment. Not that I have anything like that lying around or a use for it after the job! :p

[SizeDOESMatter]

I've recently stumbled across an old iMac g4:apple: which is totally broken (and in any eveny it's only a 700mhz one, so wont be of much use to me anyway). I would like to put my 1.66 core duo Mac Mini inside it, but i realise this is no weekend project at the moment.

So i've enlisted the help of my school DT lab to help me out with this one. There's a mac enthusiast who's done a bit of modding herself, too.. so it's fingers crossed. :)

After some extensive research- there's nothing i can conclude about that LCD panel... it seems like it's going to have to go. This is fine, i suppose:confused: , but does anyone have any ideas about an LCD i could purchase to sit in its place?.. I want to make this clear-- I would like the imac to look (ALMOST) Identical to the way it was intended to be. It's a style icon and should stay this way. Now.. a 17" widescreen LCD panel is purchased pretty cheap on ebay these days.. but i need one which will be smal enough with its case removed to fit snugly inside the apple casing, and one which isnt too heavy for the arm to support. I've got my work set out, right?

I've got my mac mini :apple: sitting here.. ready to be de-shelled and inserted into the imac g4. Might eventually put a faster HD inside it.. but everything else is staying the damned same. It's stupidly stable, and coming from a couple of self built windows disasters, I intend to keep it that way.

To summarise; i need to know:
-Is there enough space inside the arm to fit a regular vga/dvi cable?
-Which LCD panels people might have experience with using and taking out of their (usually ugly) exterior casings.

I will keep you posted. iMac G4 :apple: will be with me shortly.

PS: To anyone who doesnt mind wasting electricity (and a perfectly good computer) VNC is always a way of using another screen, and works pretty darn good over a wired connection.. but i understand this wont be to the liking of you guys.:D :p

[kgarchar]

I've been wanting to do this for as long as I can remember, so someone please figure this out. :D

[fuyutsuki]

For anyone needing physical rather than electrical info by the bucketload, check this place out:

http://home.earthlink.net/~strahm_s/manuals.html

The flat panel iMac service manuals are present and correct. :cool:

[supermeerkat]

I've recently acquired a g4 iMac shell - the m/b and lcd display missing, but everything else present. After being put off by the cost of a 15" LCD display (£150) I wonder has anyone considered getting the innards of the 15" TFT monitor into the LCD casing?

Would anyone participating in this thread, with a 15" g4 iMac, be able to provide me with the dimensions of the LCD display without the external casing? If you could, I'll buy you a drink :)

[SizeDOESMatter]

.so i have my imac g4 now.. the 17in model

I've posted a little video on youtube showing you what i've achieved so far, and where I need some help with the arm itself, taking it apart and then removing the wires inside... many thanks again for all your continued support :)

here is the youtube link: http://www.youtube.com/watch?v=5asq2kFduPk

[lunchbxotheman]

OK, I did some digging around inside of the LCD and found a few things out about the connectors. The big black connector that has the INVERTER CABLE, speaker, and FAN marked on it, also has two unmarked wires leading into the LCD. Inside, you can see the two wires go to sperate places. One goes to the mic, the other to the status LED. So basically the big black connector is useless to us.

The silverish wire leading in to the LCD through the arm is marked as 'antenna' in the LCD, but I think it's more of a ground than anything else. Can anyone confirm that? It doesn't look like it is even wired to anything. Maybe it's power?
The ONLY wire I think we need to be worrying about is the 21-pin connector shown here (http://att.macrumors.com/attachment.php?attachmentid=67307&stc=1&d=1170350345).

It splits into two sections inside of the LCD. One looks like it goes straight into the display itself. The other goes to a little chip mounted on the casing (an image processor?).

I'm sorry I don't have any pictures, I don't have a digital camera at the moment.

Hopefully this tread will stay alive. I'd love to be able to use the LCD with a standard DVI connector.

[Schtumple]

I was planning on doing this project myself a while back, although i planned to get a broken imac and use all mac mini parts (HD & DVD drive)

Take off the imacs tft screen (as the connector wiring seems to be too much hassle for me to rewire) and replace the internal screen with a new one (dell 17inch or something) and somehow wire all the cabling through the arm again.

One day...

[MacLinux:')]

I think it is possible to hook up the video, you need a DVI/VGA adapter for the mini and an VGA connector to replace the TDMS connector on the cable inside the iMac. And of coarse a power source for the inverter on the back of the screen.

I been reading the manuals and it keeps mentioning VGA, like the miniVGA connector for the imac. If the imac screen is not working - hook up an external vga monitor to see if that is functioning. I am convinced that this is all we need to do.

What about getting the latest iMac mother board? Most likely going to need a box to place it under the dome. Just a thought.

My 17" iMac 10.3.9 is still good, no USB2 (how stupid is that), but can not see trashing a good computer just to get an upgrade. But Now I am seeing a lot of programs that require 10.4 and intel only. SUCKS

Anyone done a watercooled iMac?

[pool31]

how about using screenrecycler? http://www.apple.com/downloads/macosx/networking_security/screenrecycler.html

Could you connect a Mac Mini to the iMac with a cross over ethernet cable and use the iMac screen as the Mac Mini screen? It's not elegant but does any know if it would work? Or does screenrecycler need a screen on both computers?

[fuyutsuki]

how about using screenrecycler? http://www.apple.com/downloads/macosx/networking_security/screenrecycler.html

Could you connect a Mac Mini to the iMac with a cross over ethernet cable and use the iMac screen as the Mac Mini screen? It's not elegant but does any know if it would work? Or does screenrecycler need a screen on both computers?

That could be an option of sorts for those with a working iMac G4, which doesn't include me. Mine is hosed from the neck down.

As for your question about the Mini needing a display or not, you could ask the developer at www.screenrecycler.com as I see no obvious answer to the question and have never tried the app; sweet as it may be.

VNC (which screenrecyler uses) generally doesn't feel like nearly as good as using the computer directly. It's more of an answer for remote administration in my view, or the occasional dual monitor setup if responsiveness on the 2nd display/computer isn't crucial.

I'd much rather put a near-silent Intel Mini into an iMac G4's case than have a mixture of both with the inconvenience doubled.

[pool31]

I'd much rather put a near-silent Intel Mini into an iMac G4's case than have a mixture of both with the inconvenience doubled.

I completely agree. My iMac G4 has only a screen working now as a power surge blew the power connector for the hard drive. It still works with the os on an external drive, so 'screenrecycler' and an extra Mac Mini could easily end up as twice the hassle.

So, this thread comes back to the main issue, how to reuse the screen from an iMac G4 and connect it to a Mac Mini. Once that is solved (unfortunately way beyond my technical ability) then I'm sure squeezing the Mac Mini into the dome is the easier step.

Anyone had any joy with the screen connections? Now that Apple have surprisingly upgraded the Mac Mini, it may be really worth solving?!

[rollercoasternd]

Has anyone made any progress on switching the original screen with a new LCD, I would like to do this with the 20in iMac, not many people talk about that one, plus they are hard to find, I did a Froogle search and found only 2. Plus with the recent upgrades to the mini's this is looking even more appealing.

[casesensitive]

Ok, it would seem that trying to get the existing display in the iMac to display a signal from the DVI output of a mac mini is a dead loss, the lack of image processing chip on the display would be a killer. But all is not lost!
I found this:
http://homepage.mac.com/mactechg4/PhotoAlbum22.html
It looks that you could pipe anything you want into the iMac 'neck', including stripped DVI and power cables for an off-the-shelf 20.1" LCD.
At this point all we've got is the iMac case left of course.. But with 3.5" SATA drives and a full-height optical drive (maybe even Blu-ray!) this could be something pretty special.
Mac Mini DVI -> up the neck to an identically-sized LCD in the iMac housing, at any res.

With my beautiful iLamp approaching end-of-life, it's likely to get replaced by a 20" Intel one soon, assuming binuses are what they should be, and resale value on the old ones are worth spit, so I might go ahead with it anyway.
If I get it going, I'll post the whole thing here.

[fuyutsuki]

Interesting slides and a nice idea. :cool:

[iToaster]

I'm determined to do this with an iMac G4 and a mini, as soon as I get the iMac and mini. I've been trying to work out the screen dilemma, and figured a new display would be in order. However, the display cables might be too thick for the neck :(

[rinux]

Ok boys ! It is time that we nails this project. I have a 700 MHz iMac and a Mac Mini 1,5 GHz Solo.

The first step is to solve the LCD connection. Since I´m a Automation engineer, I could probably solve this one if you guys give me some time. Just incase I can´t handle it, 3 of my friends works with digital technics. Give me a week or so...

Hang in there guys ! We are solving this one no matter what since the iMac luxo is the most beautiful mac ever made!

Rino

[rinux]

Hi again, I have been able to hook up with a lcd adapter. Can someone please help me with how to connect it to the apple screen ?

[jamiebp]

i just took my imac g4 apart earlier
gonna put a new monitor into it feed the vga cable down the neck rewire it once its in the base.

then all i need is a mac mini to put inside
anyone got one for sale or as a early christmas present ??

only problem i see is getting a new monitor power cable down the neck think i may just have to drill a hole in the back of the casing of the screen..

jamie

[jamiebp]

i just seen the post with the photos of the neck being taken apart how do u get the pins out with the 3 dimples ???

[dcbphoto]

I just found this thread while looking for a way to put a mini into the case of my iMac G4 700MHz. It's getting on in years, and I really need a new computer, but I love the design of the G4, and I have been playing around with the idea of putting the guts of an Intel mini into the case. This thread has given me hope that it can be done, but the display seems to be the big issue. So, has anybody figured this out yet? Has anyone been able to do any of this successfully? I really want to keep the original LCD to maintain the look of the old G4. I have never modded a computer before, and this seems to be a pretty involved project, but I really want to try this. My G4 works perfectly, I just need more power under the hood!

[jamiebp]

i dont think that u will b able to keep the screen im planning on replacing it as soon as i can get a 15inch lcd then figure out how to open the neck.
but i think this thread has gone a bit dead and people have found it too hard or done something else .....

if u read the earlier posts it will tell u why u cant keep the screen something like the part that you would have to make would cost more than it was worth..

[dcbphoto]

Yeah, I think it might be a lost cause. Seems like people have lost interest in this project due to the screen issue. Are you talking about taking the screen out of the enclosure and just putting a new LCD in it's place? That would work, and it would solve the issue of keeping the look of the computer intact. That would also solve the issue of the connector, as the new screen would likely have a DVI connection - just plug it in to the mini. A power source would then be the issue. Maybe this is more trouble than it's worth, but I might try it after I get a new computer (MacBook Pro, please!) I can't really afford to not have a working computer, so I might try this as a side project.

[jamiebp]

i dont see the power supply being any more of a problem than the dvi/vga cable just open up the neck and youve got a winner just finding it hard to get a 15 inch screen no one really sells them except on ebay and then still delivery of 15 quid for a screen is a bit ridiculous !!!

i think its worth doing just for the bragginf rights of saying i was the first and check out how much better my mac mini looks compared to a stupid dell system

it just makes sense

[ncpiment]

Hi Everyone.

I been trying to use also the screen independently but its been quite hard as you guys know lol

I know this thread as been dead for a while but i hopping that someone by this time managed to do it by now.

[fuyutsuki]

Hi Everyone.

I been trying to use also the screen independently but its been quite hard as you guys know lol

I know this thread as been dead for a while but i hopping that someone by this time managed to do it by now.

Not me.

[ncpiment]

Not me.

Oh right. Is there any progress at all being made or was made?!

[unnamedculprit]

Hi. Short introduction: First post on forum. Own neither iMac G4 nor Mac Mini, but searching ebay for both.

I plan to go down the original screen route, by having a good look at the TMDS specification, and the feasibility of making a controller board for the original screen. I've just done a digital project to finish my degree, and want to keep my brain active this summer.

I've been looking at this on and off for well over a year now; with the main set-backs being the availability of G4 iMacs, and the amount of funds available to purchase said item.

The links to the service manuals (posted earlier on the thread) are now dead, so if anyone knows of where I could obtain a G4 iMac service manual, I'd be very grateful.

If I find out anything of any use, I will post it here.

[hackdeplus]

Hale and hearty this thread must be by now. Time to dig for the solution to the twin displays made possible by the 2009 Mac Mini. I'm in this one for the long haul, and will find a clever solution, I hope. Here's my mock-up for the two flatscreen G4s I've got laying around here:

[fuyutsuki]

Hale and hearty this thread must be by now. Time to dig for the solution to the twin displays made possible by the 2009 Mac Mini. I'm in this one for the long haul, and will find a clever solution, I hope. Here's my mock-up for the two flatscreen G4s I've got laying around here:

Ah! Not only adding DisplayPort to the mix (all Macs are moving to it as said by Steve at the Unibody event) but doing the whole thing twice, too!

I salute your optimism. But fear for your mind! ;)

[unnamedculprit]

AHA!

I now am in possession of an iMac G4 17" 1Ghz.

and have found a service manual here: http://www.sduk.baconeggs.com/images/dmm/imac17-inch.pdf

I'll let you know my progress as I go :)

[Digitalflick]

I'll let you know my progress as I go :)

Please do! :)

[applefan1997]

Finally! I've been following this thread for a long time. I have a 800MHz G4, and while it still runs, it's nice to know that there are still options of giving it life if it needs. Anyways, the obstacle in this project seems to be the display, and trying to rewire it.
Here's what I think:

Don't bother reusing it. Try getting a other LCD display of the same size, and try to remove its casing so it can fit in the iMac display casing.

Most LCD's are still too fat due to the power supply. However, the Apple Studio Displays (15 (model 2454) and 17") have no power supplies to thickn the case. They are powered by ACD. Once disassembled, they should fit in the iMac (15, 17"). There is no 20", so owners of 20" iMacs may have to try something different.

Getting the cable through the neck is the next part. I am not completely knowledgeable of the internal of the arm, so a cable may or may not pass. If you can deal with it, you can drill a hole through the back and bypss it by having the cable pass down.

A ADC to DVI adapter would have to be used.

The top case of the Mac Mini could be removed, and if it's possible, a full size CD or HD drive could be installed.

Cable extensions could be used to make the ports much cleaner.


What do you think?

[newspimp]

Hello all!

Like many of you, I've been wondering what to do with a beloved iMac G4. Where I work, we're retiring several 20" models, and most of them have been perfectly operational.

Two of them, however, are not. One seems to boot up, but has no video and the other partially boots, but never completes from DVD or from the internal hard drive. My wife and I have both got functional models, but I've wanted to take the one that has an operational LCD and adapt it to a Mac Mini I have.

I've been researching the information for a bit now, and using the information found near the bottom here (http://www.applefritter.com/node/18351) it looks like many of the TMDS cable wires have been identified. There is, however, a lack of three of the wires being known for sure, and two open ports.

TMDS is the signalling protocol for DVI, so based on the DVI TMDS protocol spec (http://www.ddwg.org/lib/dvi_10.pdf), a single link DVI channel requires only the 0, 1 and 2 data channels and associated shield pins, and the TMDS clock. This accounts for most of the pins. 1-4 (Vcc and GND) and 17-21 are still unknown assuredly.

Looking up the specs of the closest SilImage DVI processor chip, a PanelLink receiver chip that seems to corroborate (as well as i can tell; still picking this all up) the ideas about a DDC link as well.
(http://www.siliconimage.com/docs/SiI-DS-0023.pdf)

So, I've removed the LCD panel from my dead 20" and found that it runs an IDTech 20 WSXGA+ IPS panel, model M201Z2

And located the tech specs for it (http://www.gblcd.com/datacenter/idtech/M201Z2-M01.pdf) (found open on Google) Which list the specific pinouts for the TMDS in cable to the 30 pin flat connector on the back of the LCD panel.

Three channel TMDS with shields, DDC 3.3/5v power, a DDC channel. Yep, looks like it should be DVI compatible.

Now, tomorrow or over the weekend I'll be tracing out the TMDS -> 30pin wire and ensuring that the referenced connector pinout is right and then try adapting it to a standard DVI. That and working on getting the pinout for the Apple inverter board, which is bolted to the backside of the back chassis of the LCD housing and is connected to the joiner wire that joins the inverter, microphone, power indicator LED, fan and speaker connectors.

I'll have pictures as well, but it does look a little bit more attainable than a laptop LVDS display.

[fuyutsuki]

Best of luck!

[Phunker]

Hey ! I´m desperately looking for a imac g4 power supply. Can´t find one anywhere and my girlfriend is close to tears because her precious imac is broken. If you guys dismantle so many, does by any chance one have a spare power supply? it´s a 700/800mhz model.
Cheers
Andre

[12soldier]

I got the 1gz 17" model and was looking at all the possibilities for this model as well. All I really want from is it to be sort of an iPod drone. I have so much music and videos that my hard drive is full on all my computers and wanted to narrow that down to only one. I love the design, so I would just like to put the intel chips and new graphics on it rather than simply buy a new one. Plus I hate getting rid of stuff if I can help it. Especially when they look so nice already.

Another idea I had was to change out the display with a better one and make myself a new base that can handle the mac mini, but looks like the new Mac Pros with the perforated metal. Anyone know where I can find this type of metal for this operation?

[MisterDNA]

I have a 20" iMac G4 with a bad logic board that I am looking to do the same thing with since I chipped a corner of the CPU die during a RAM upgrade (heatpipes didn't let go of Faraday Cage). Fortunately, I am an Electronics Technician who wears the engineer hat once in a while and this would be a dynamite hack.

This is do-able.

First of all, big thanks to newspimp. Friend, you have saved me a fair bit of time by linking the datasheets.

While I can do the hardware stuff, it would appear that software is something I'm not well-versed in on Macs. I do, however, know that Nvidia GPUs have an option to set display scaling or GPU scaling as a default rule. Macs already use display scaling and the 20" panel has its own GTF-based specs for timing. This is a huge bonus and I'm pretty sure the DDC lead on the panel carries a signal that Windows and OSX can understand.

I believe that either OS will default to any resolution the DDC data says is available when the GPU agrees. But there's still the chance for install screens under Windows to run at a completely different resolution from what the panel will directly take if you don't have GPU scaling enabled. I need to do more DDC research to see exactly how it works.

While the panel expects 3.3VDC nominal on the TMDS signal lines, I believe standard DVI output for external cabling is 5VDC, but I will have to make sure. If a level-shifter is needed, I believe I have access to the right parts to drop 5VDC to 3.3VDC at this kind of clock rate.

Personally, I'm going for an Nvidia Ion platform hack, not a mini, but it should yield a great foundation for other projects.

[newspimp]

Anytime, MisterDNA! If nothing else, you can hopefully fill in the gaps that I have.

Done a bit more research this morning on the inverter board issue. The Pg. 4 linked datasheets are great for the data side of things (IIRC, you are right; DVI uses 5vDC for signal versus the LCD 3.3vDC input) the backlighting was my next concern.

The inverter inside the 20" LCD is an Apple product, and it looks like someone has done initial pinouts from the multi-cable from the G4 logic board to the inverter input.

http://www.electro-tech-online.com/general-electronics-chat/88397-ccfl-inverter-pinout-help-n0ob.html


The inverter has 8 pins in as described below. I can supply pictures of PCB if needed.

Blue = 11.93v
Red = 11.93v
Blk = GND
Blu = GND
N/C
Yel = .2mv
Prpl = 3.262v
Orng= no voltage detected

So, it seems to me that with the 12V (blue and red go to fuse on inverter PCB) and 3.3v, the lamps should ignite correct?

However, I am under the assumption that the 3.3v is the on and off and the Yel & Orng are for brightness control. Does that sound correct?

I need to get a new set of leads for my DMM (old ones are a bit too used and dull to get into the thin spaces needed) and then I can finish the signal cable trace.

Also, as soon as I find the cable for my digital camera, I'll have the pictures I've taken up and ready.

I'm thinking a small box, with the TMDS connector and the multi-tap connector on one side and a DVI, power supply and jumpers for the microphone, status LED, fan and speaker on the other. Getting an EaglePCB diagram shouldn't be too difficult to workup so it could be reproduced and reliable.

[MisterDNA]

That link is excellent.

I am wondering whether the voltage on the purple lead is proportional to the brightness of the backlight. Based on the low reading I see there, I am thinking that since the backlight was barely on when the reading was taken, the inverter was just barely on and not even in-spec for minimum brightness as the datasheet goes. Maybe full brightness reads 3.3V?

It looks like the ~3.3VDC lead was meant to run an IC while the 12VDC rails are used as-is for inversion.

I have full access to the X-ray at work and should be able to reverse-engineer a block diagram for this and at least find out how the brightness is controlled.

Breakthrough: The DVI spec lists 3.3V nominal signaling with a 4VDC maximum just like the LCD panel. The panel appears to have a DVI interface. I see no intermediary IC between the panel harness and the GPU so it's likely being driven directly from the Geforce FX5200 Ultra. I can use the X-ray to find that out for certain as well.

I will have to find a datasheet for the GPU BGA in order to know what each pin is, though. But just to make sure.

I do see that we need the EDID pins wired to a DVI connector in order to use the panel with a standard DVI connector. Otherwise, the GPU BIOS would have to know to only expect a 1680x1050 panel and that's a lot more work than running three wires.

Interesting to note: Silicon Image came up with TMDS and called it PanelLink. It seems that with the addition of DDC (EDID) for plug and play, that became the standard we know as DVI. I have a 15" Apple display taken apart at home that uses PanelLink and it's from 1998. DVI was created April 1999.

[MisterDNA]

I have learned a little bit more about the interface and it's time to give it a go.

I have the guts from a 15" Apple panel from like 1998 that uses the same panellink connector as the 20.1" iMac panel. The backlight on the 15" panel is completely toasted, but I'll be able to see the display with a flashlight. When I finish modding the controller board and isolating the Panellink connector and filters, I'm going to feed it a standard native CVT XGA 60Hz signal and see what happens.

I missed this the first time around, but the panel datasheet refers readers to the datasheet for the TI TFP403 PanelBus digital receiver. Second bulletpoint down the list:

Digital Visual Interface (1.0) Specification Compliant

It's DVI with a different connector that lacks EDID signals. I can run three wires inside the arm of a 20" iMac. Not sure about any other size.

In addition, I can replace this receiver with the pin-compatible TFP501 to make the panel HDCP compliant. In fact, there's a very slight chance it might already have one in it. I will cross that bridge when I reach it.

While the stock backlight still hasn't been figured out, I did source a six-tube low-profile inverter. The price makes me think I'd be better off reverse-engineering the stock one, however. After all, not everyone has an X-ray machine.

My plan has changed from an Nvidia Ion stuffed inside the guts to having the unit connected via an umbilical to a larger system placed out of sight. Imagine what appears to be an iMac G4 with the heart and soul of a fire-breathing quad-core workstation.

This is on like Donkey Kong.

[newspimp]

I've got an 8-core Mac Pro and two busted iMac G4 20" models ready to go!

Now, I wonder if my panel is fully capable for DVI with the EDID, since the panel itself does accept it. I can see why the 15" may not, but the 20" model should. If so...

I think I'm going to pull a DVI cable apart later today and start on that.

[MisterDNA]

I've got an 8-core Mac Pro and two busted iMac G4 20" models ready to go!

Now, I wonder if my panel is fully capable for DVI with the EDID, since the panel itself does accept it. I can see why the 15" may not, but the 20" model should. If so...

I think I'm going to pull a DVI cable apart later today and start on that.

That's a killer machine. It would look even more killer with a pair of iMac G4s as displays.

I'll pull my inverter this weekend and head to work off the clock to see if I can get a partial schematic figured out under X-ray. I might not even need the X-ray as much if I can find datasheets for the components on the inverter board. The larger SOIC has me the most curious. I can't quite read the numbers on it in that picture at the other forum you posted the link to.

I did find another supplier for inverter boards and one could be had for $26 in six-tube form, but it requires modification of the tube connectors to accept the doubled-up ones. Also, I don't think it's adjustable.

Worth mentioning: The panel has a little more strict standards for power input than what's considered spec for an ATX power supply. While ATX allows +-10% on the 12V rail, the panel's Vcc of 12VDC is only rated for +-5%. The supply inside the iMac should of course operate within this range and, according to the USB 2.0 iMac G4 service manual, the supply is live on at least the 12VDC rail as long as it is plugged into the AC main.

It might be better to use the iMac's PSU to run the panel. In my case, I will be putting a USB optical drive and eSATA-connected hard disk (or two?) and powered USB hub in the gutted iMac. All of these will surely run from the stock PSU with better lifetime on the PSU for lack of the logic board. After removing the guts from my own G4, it's dangerously top-heavy when the neck is all the way out and down. If you aren't going to put drives inside yours, weight them with a sandbag or something.

[newspimp]

That's a killer machine. It would look even more killer with a pair of iMac G4s as displays.

I'll pull my inverter this weekend and head to work off the clock to see if I can get a partial schematic figured out under X-ray. I might not even need the X-ray as much if I can find datasheets for the components on the inverter board. The larger SOIC has me the most curious. I can't quite read the numbers on it in that picture at the other forum you posted the link to.

I did find another supplier for inverter boards and one could be had for $26 in six-tube form, but it requires modification of the tube connectors to accept the doubled-up ones. Also, I don't think it's adjustable.

Worth mentioning: The panel has a little more strict standards for power input than what's considered spec for an ATX power supply. While ATX allows +-10% on the 12V rail, the panel's Vcc of 12VDC is only rated for +-5%. The supply inside the iMac should of course operate within this range and, according to the USB 2.0 iMac G4 service manual, the supply is live on at least the 12VDC rail as long as it is plugged into the AC main.

It might be better to use the iMac's PSU to run the panel. In my case, I will be putting a USB optical drive and eSATA-connected hard disk (or two?) and powered USB hub in the gutted iMac. All of these will surely run from the stock PSU with better lifetime on the PSU for lack of the logic board. After removing the guts from my own G4, it's dangerously top-heavy when the neck is all the way out and down. If you aren't going to put drives inside yours, weight them with a sandbag or something.

The numbers on the largest IC chip on the inverter board I have is as follows... It's the one right next to the five horizontally mounted and sealed caps, numbered U2.

OZ971S
0342B1
B33971.1A

[MisterDNA]

The numbers on the largest IC chip on the inverter board I have is as follows... It's the one right next to the five horizontally mounted and sealed caps, numbered U2.

OZ971S
0342B1
B33971.1A

Found a cousin! O2Micro makes the OZ971 and it would seem that the OZ964 is basically the same thing, but newer and in single form as opposed to dual. I will still have to do some X-ray work to make sure, but this gives us a lot of new info.

The parts in the old family from which the OZ971S comes includes: OZ960, OZ961, OZ970, OZ971 and OZ963. I haven't been able to find datasheets on any of those.

* Supports wide-range voltage input applications
* Built-in intelligence to manage ignition and normal operation of CCFLs
* 85% efficiency vs. typical 70% efficiency of conventional designs
* Internal open-lamp and over-voltage protections
* OZ960/961: Integrated burst mode control, and wide dimming range (10% to 100%)
* Simple and reliable 2-winding transformer design
* Supports multiple CCFL lamps
* Constant-frequency design eliminates interference with LCDs
* Low stand-by power
* Packages available:
o OZ960: 20 SSOP and 20 DIP
o OZ961: 20 SSOP
o OZ970: 16 SOP
o OZ971: 28 SSOP

It looks to me like the dimmer circuit will have to be set up for a minimum of 20-25% brightness to protect the tube electrodes if the circuit isn't already set up that way.

It appears that there are supposed to be two supplies feeding the inverter. There's the supply voltage for the transformer inputs (~12VDC) and a lower voltage supply for the chip itself. It's possible that the purple 3.3VDC purple lead is this supply, but it could also be an enable line. Either way, this all revolves around the Yellow, Purple and orange lines.

Judging by the reference circuit I saw in the cousin part's datasheet, it looks to me that the brightness is determined by a voltage between .6VDC and 2.1VDC with respect to the DC ground of the inverter board.

There are variable DC power supplies at work that can be used for this investigation. I can even limit the current to prevent damage if I get the connections wrong even after X-ray inspection.

[WebmastuhB]

Awesome thread...

Phunker - I can probably get you a power supply if you need one. I can probably get a few. I am not sure if they work, but they should. I guess PM me...

And to the rest of everyone on this thread - good work guys!

I'd love to use the existing LCD on the iMac G4, and replace the motherboard with some kind of kick ass intel board (so I can get the latest software.) I was hoping there was a dongle or a connector or something that would allow me to hook the existing display with a newer motherboard (or a DVI connector, or a VGA connector, or something...)

Any progress being made on being able to use the existing display?

Anything I can do to help?

[MisterDNA]

Awesome thread...

Phunker - I can probably get you a power supply if you need one. I can probably get a few. I am not sure if they work, but they should. I guess PM me...

And to the rest of everyone on this thread - good work guys!

I'd love to use the existing LCD on the iMac G4, and replace the motherboard with some kind of kick ass intel board (so I can get the latest software.) I was hoping there was a dongle or a connector or something that would allow me to hook the existing display with a newer motherboard (or a DVI connector, or a VGA connector, or something...)

Any progress being made on being able to use the existing display?

Anything I can do to help?

The panels I have seen so far use a DVI-compliant TMDS signal. The plug and play features are not enabled through the iMac's display data connector, but they are present at the panel.

The backlight has not been figured out yet. I will be doing that this weekend with the x-ray machine at work if I get the chance. I will also be hacking an old controller board into a suitable adapter to attach to a cut up DVI cable.

All I need is time.

In the name of making our mods look good, someone needs to find a way to thread a three-conductor wire down the iMac G4 arm so the DDC/EDID wires are available in the DVI implementation. If we don't have those wires and the data they carry, OSX users may be out of luck unless there's a way to manually configure a display with one mode and only one mode available like you can with Windows. Since I'm not hooking mine to a Mac or Hackintosh, I won't be exploring the nuances of OSX.

If there is anyone who can get readings for the unknown inverter leads before I do the X-rays (which aren't going to answer everything immediately by themselves), I say do it.

There is another possibility: Although my iMac wouldn't work at all while at room temperature, it would start up and even run for an hour or two with that powerfractal program while extremely cold out in my shop. If I can solder a piece of 8-conductor CAT-5 to the logic board for sniffer wires, thread them through the optical drive slot and take readings while messing with the brightness, I should have all of the data we need regarding the inverter.

Actually, I can probably scrounge up at least three multimeters and a dual-trace oscilloscope to see everything at a glance.

[WebmastuhB]

The panels I have seen so far use a DVI-compliant TMDS signal. The plug and play features are not enabled through the iMac's display data connector, but they are present at the panel.

The backlight has not been figured out yet. I will be doing that this weekend with the x-ray machine at work if I get the chance. I will also be hacking an old controller board into a suitable adapter to attach to a cut up DVI cable.

All I need is time.


Cool Stuff! Well good luck...



In the name of making our mods look good, someone needs to find a way to thread a three-conductor wire down the iMac G4 arm so the DDC/EDID wires are available in the DVI implementation. If we don't have those wires and the data they carry, OSX users may be out of luck unless there's a way to manually configure a display with one mode and only one mode available like you can with Windows. Since I'm not hooking mine to a Mac or Hackintosh, I won't be exploring the nuances of OSX.


I wouldn't mind building a hackintosh out of this. I imagine a small form factor intel based mother board could be purchased cheaply, perhaps it has a DVI port on it, and this monitor cable could just be hooked to that.

I'm more of a software guy and less of a hardware guy.



If there is anyone who can get readings for the unknown inverter leads before I do the X-rays (which aren't going to answer everything immediately by themselves), I say do it.

There is another possibility: Although my iMac wouldn't work at all while at room temperature, it would start up and even run for an hour or two with that powerfractal program while extremely cold out in my shop. If I can solder a piece of 8-conductor CAT-5 to the logic board for sniffer wires, thread them through the optical drive slot and take readings while messing with the brightness, I should have all of the data we need regarding the inverter.

Actually, I can probably scrounge up at least three multimeters and a dual-trace oscilloscope to see everything at a glance.

Interesting stuff, but I am a little lost. I'm not into the nitty-gritty of hardware. Sorry.

But SWEET! Keep me posted, this is pretty interesting.

[newspimp]

In the name of making our mods look good, someone needs to find a way to thread a three-conductor wire down the iMac G4 arm so the DDC/EDID wires are available in the DVI implementation.

It may bot be present or wired up in the 15" model, which was pre-official DVI spec, but the 20" cable does have the three wires for DDC/EDID. Pins 17,19 and 20 IIRC.

So, we may be able to pipe the DDC/EDID through those wires since they're already present and at least on my 20" hooked up to the proper inputs on the LCD controller board.

Gotta love travelling for work. Catching up on about 200 e-mails today!

[MisterDNA]

I put the iMac back together and I'm chilling it down outside in my shop. Since it's supposed to get down in the teens overnight here, I should be able to find out whether the inverter will run.

[MisterDNA]

I put the iMac back together and I'm chilling it down outside in my shop. Since it's supposed to get down in the teens overnight here, I should be able to find out whether the inverter will run.

Okay, the iMac didn't start up after being chilled way down. I will have to go about this the hard way and I didn't have time for that this past weekend.

[newspimp]

Okay, the iMac didn't start up after being chilled way down. I will have to go about this the hard way and I didn't have time for that this past weekend.

I have a 20" iMac inverter I can send you to try out if needed. I'm not 100% on whether it's working properly, though. Also, may be useful in determining if they used different ones for the different panels.

[harry454]

yeah someone should try it out and see if it works, if you do post a picture!

[MisterDNA]

I am in my workshop right now, pulling the iMac G4 apart for the run at reverse-engineering. I have it all torn down and the wrapping taken off of the inverter board. The board is two-layer so I may not actually need to use the X-ray machine unless there's some thing hidden under the OZ971S controller IC. Since we should have an outline of where pins connect to start with, I will put some info here.

1,2: Vcc 12VDC
3,4: GND
5: Connects to R2 (which measures 10Kohms), which is in series with R3, a 47Kohm resistor the other side of which is connected to a fat trace with one side of C10 to Pin 28 of the OZ971S controller IC. This is going to be important for sure, but it's supposedly not connected according to research newspimp posted.
6: Connects to R5, which I can't read, but get a reading of 4Kohms off of, through which we are directly connected to Pin 3 of the LM393M IC, C16 to GND, R8 (which is .5Mohm and connects to the GND through C17)
7: Connects to the positive side of D3, through which we connect to the collector of Q7, also branching out through a 10Kohm resistor to Pin 28 (GND) of the OZ971S and Pin 1 (Silkscreen says 1 while datasheet for part says Pin 2) of Q5 (which is etched "1AM" on top, making it a 3904. The silkscreened Pin 2 of this part is connected to the negative side of the ZD4 Zener Diode
8: Connects to the Bases of Q1 and Q2, but also through a 1Mohm resistor to the system ground. You'll like this: The collectors of Q1 and Q2 (controlled by Pin 8) go through 30Kohm resistors to the collectors of what look to be transistors on a circuit bank that monitors the low side of each lamp.

The high side of the lamps appears to be monitored through pin 11 of the OZ971S IC.

Pins 5,6 and 7 on the comparator aren't being used, meaning that on a dual comparator IC, there's only one comparator being utilized. I recall comparators being part of how the inverter controller does its thing regarding brightness.

Pin 6 of the OZ971S is connected to Pin 8 of the comparator, making that the supply for the comparator chip.

This is very rough and I'm posting it as I write it.

[MisterDNA]

Inverter pins from the motherboard:

Between purple and yellow: Resistance = 20Kohms
Between orange and yellow: Positive on yellow, negative on orange: 1.7Mohms, out of range the other way
Between Orange and Purple: Positive on Purple, negative on orange: 1.7Mohms, out of range the other way

Tested as diode rather than resistor, I see voltage drops of 1.414VDC with the leads arranged the 1.7Mohm way and 1.46 the out of range way.


DDC/EDID functionality confirmed on iMac G4 20" display panel!

Pin on motherboard connector and where it goes:


Pin 17: V-EDID (Pin 15 on bare LCD module)
Pin 19: Clk-EDID (Pin 17 on bare LCD module)
Pin 20: Data-EDID (Pin 18 on bare LCD module)


Look here:
http://discussions.apple.com/thread.jspa?threadID=1907977&tstart=0

This could be really interesting. It's the same user whose inverter pinout we've been referring to. It would seem that the inverter blew an inductor and wouldn't fire up so that would explain why nothing ever reached a solid conclusion in that thread. This user fitted the display with a generic inverter and found that while the iMac uses a voltage of between .88VDC and 3.3VDC for brightness level, the generic inverter used 0-5VDC.

I signed up for the apple forum and posted there. The whole thing has played out over a couple of weeks so it should be possible to get new data if I don't figure it out before he replies.

[MisterDNA]

I've figured out a circuit for the dimmer. It's based on a potentiometer and the working voltage range of between .9VDC and 3.3VDC with 3.3VDC being max brightness. The 0.9VDC is a hard minimum and must never go below that so I'm going with a safety.

From a 5VDC rail:

R1 = 470 ohms 1% tolerance
Output at the end of that.
R2 = 0-1K potentiometer (a really good one)
R3 = 110 ohm 1% tolerance (may need to use 100ohm and 10ohm)
Ground after R3

I really wish there were something more elegant than this within easy reach. I don't like analog controls and I suppose I could use a resistor ladder of four bits or something like that off of a microcontroller. It would be cool to have that as one feature of a secondary system driven by the microcontroller and including an LCD display for system data and other functions.

An ATMEGA128 would work very well for such an application, but so would a Parallax Propeller and I don't know those yet.

[tjka4321]

I just wonder if it is possible to put a mini-itx motherboard to make a PC into imac G4 dome and use an add2 graphic card with "TMDS output" to utilize the imac's flat panel.

My imac G4 17" is just running its screen saver everyday. What a waste!

TIA for any suggestion/advice.

[newspimp]

I just wonder if it is possible to put a mini-itx motherboard to make a PC into imac G4 dome and use an add2 graphic card with "TMDS output" to utilize the imac's flat panel.

My imac G4 17" is just running its screen saver everyday. What a waste!

TIA for any suggestion/advice.


Nope. At least not as you've said it. One thing that we've definitively come to is that the video input for the iMac LCD is *NOT* TMDS. The iMac G5 and subsequent Intel models is TMDS, but for all but final testing, the iMac G4 video input appears to be PanelLink for early 15/17" models and full-blown DVI for later models.

[MisterDNA]

I believe you are confused, newspimp. DVI and TMDS are the same thing. If you were to replace TMDS in your post with LVDS, you'd be right.

Fact: TMDS is a form of LVDS signalling. LVDS stands for Low-Voltage Differential Signalling. TMDS stands for Transition Minimized Differential Signalling. Both are low-voltage.

Transition minimization is a kind of protocol used to reduce the radio frequency of the signal on the lines to allow higher resolutions and longer line lengths. I could go into how it works, but anyone can look that up and it's easier to say why they do it.

They are not, however, directly compatible. There are GPUs with switchable modes. That's a build-to-order thing and changing the wiring to convert to the other means messing with the GPU at the ball-grid level if you can even find a datasheet for the GPU in question and then writing your own firmware since you aren't likely to get significant help from the GPU vendor.

I haven't worked on the iMac project for a while. I'm stuck waiting to find a good DVI breakout or a video card I'm willing to sacrifice to the cause.

[newspimp]

I believe you are confused, newspimp. DVI and TMDS are the same thing. If you were to replace TMDS in your post with LVDS, you'd be right.

Fact: TMDS is a form of LVDS signalling. LVDS stands for Low-Voltage Differential Signalling. TMDS stands for Transition Minimized Differential Signalling. Both are low-voltage.

Transition minimization is a kind of protocol used to reduce the radio frequency of the signal on the lines to allow higher resolutions and longer line lengths. I could go into how it works, but anyone can look that up and it's easier to say why they do it.

They are not, however, directly compatible. There are GPUs with switchable modes. That's a build-to-order thing and changing the wiring to convert to the other means messing with the GPU at the ball-grid level if you can even find a datasheet for the GPU in question and then writing your own firmware since you aren't likely to get significant help from the GPU vendor.

I haven't worked on the iMac project for a while. I'm stuck waiting to find a good DVI breakout or a video card I'm willing to sacrifice to the cause.

Completely right... Had TMDS on the mind. What kind of DVI video care are you looking for? I have quite a few in spares right now...

[djuro]

Ok, guys, how about if we change approach? I was thinking of upgrading the screen as well. Samsung is producing LCD panel 15" (4:3 aspect ratio, check link http://www.blisscomputers.net/servlet/the-46885/SAMSUNG-LTN150PG-dsh-L04-LAPTOP-LCD/Detail ) which should fit in nicely. Now, my thinking was: if we do know what kind of display we do have, and we can get documentation for it (I have found it on 'net) is it too much hassle to produce electronics that would convert it defacto to monitor. That way we could just plug it in to DVI output of mini and we have solved 85% of our problems? After all, this LCD panel has 1400x1050 pixel resolution which would make a nice hike comparing to original 1024x768? The price is also OK, not too steep and the Lamp would become modern computer in EVERY respect?
Now, I have a degree in engineering so I can contribute when it comes to packaging, but this electronic stuff is beyond me.
Perhaps MisterDNA could do something about it?

[newspimp]

Ok, guys, how about if we change approach? I was thinking of upgrading the screen as well. Samsung is producing LCD panel 15" (4:3 aspect ratio, check link http://www.blisscomputers.net/servlet/the-46885/SAMSUNG-LTN150PG-dsh-L04-LAPTOP-LCD/Detail ) which should fit in nicely. Now, my thinking was: if we do know what kind of display we do have, and we can get documentation for it (I have found it on 'net) is it too much hassle to produce electronics that would convert it defacto to monitor. That way we could just plug it in to DVI output of mini and we have solved 85% of our problems? After all, this LCD panel has 1400x1050 pixel resolution which would make a nice hike comparing to original 1024x768? The price is also OK, not too steep and the Lamp would become modern computer in EVERY respect?
Now, I have a degree in engineering so I can contribute when it comes to packaging, but this electronic stuff is beyond me.
Perhaps MisterDNA could do something about it?

Well, the good thing, should that tack be taken, is that the mapping of the existing wiring and all of that really isn't as needed.

What we've been looking at is mapping out the inputs for the existing LCD panels and it's inverter and converting that to DVI.

If you replace the panel and the inverter, then that's really kind of out the window. If you can strip the casing off of the LCD monitor that you're looking at, and make it fit within the iMac case, the running the standard size power and DVI through the arm should be a minimal problem. You'll certainly have to cut the ends and resolder, or work up a disconnectable end that will fit through the narrow iMac arm hole, but that shouldn't be too big of an issue.

[mhfdejogn]

Whoow this stuff just blows my mind:| I've had the same idea for the last couple of weeks now. I have a 20" imac g4 on my desk at the moment, and I love it, but I would like it to have a little more power in it.
I've read through the entire threat and in seems like there is a big problem with the way the display receives it's data and power. I have absolutely NO clue how to tackle this problem, but I would like to build my mac mini in the g4 case. It seems that the only way to do this is to also replace the screen.
I hope you guys can find a way to make a converter of some sorts and make the entire process of assembly easy enough for me to be able to reproduce.

[SkippyThorson]

I just had an idea. Obviously the iMac Screen would be too difficult to connect to the board of a Mini, but what if these were closer in technological build?

My idea is this: what if the solution lies in not connecting old screen to new computer, but connecting new screen to new computer in old case.

A 20 inch iMac and Mac Mini of the same time would have a lot of the same components, right? So is it at all possible to for the new 20 inch screen with the new connectors to fit in the casing? If so, a closer set of components may be part of the answer.

[Clive At Five]

Wow, this is incredible. I've been following this thread off and on for about two years, hoping for a way to breathe new life into my original 15" 800Mhz G4 iMac. I have to confess that most of the hard-hitting stuff has gone a bit over my head, but if there's any way that a mere mortal with a modest knowledge of circuitry can help, please let me know! My iMac is OPERATIONAL and in perfect condition, except for the fact that it's slower than hell. :D

-Clive

[newspimp]

I just had an idea. Obviously the iMac Screen would be too difficult to connect to the board of a Mini, but what if these were closer in technological build?

My idea is this: what if the solution lies in not connecting old screen to new computer, but connecting new screen to new computer in old case.

A 20 inch iMac and Mac Mini of the same time would have a lot of the same components, right? So is it at all possible to for the new 20 inch screen with the new connectors to fit in the casing? If so, a closer set of components may be part of the answer.

Well, the biggest problem with using an iMac G5 or iMac Intel LCD screen is that they use LVDS connections to the LCD panel from the motherboard. This is most commonly used in laptops.

The big reason that the G4 iMac is promising is that it uses TMDS signalling and appears to be DVI compliant going in. That much I think we're fairly certain on. The biggest step right now is getting the inputs for the LCD panel inverter going.

LVDS monitors have this problem as well, but the biggest problem is that they need an LVDS to VGA or LVDS to DVI converter. Generally, these are pretty expensive and you still have the backlighting control to contend with.

Once the wiring is done for the DVI connection, and a suitable controller for the backlight is developed, then the iMac G4 LCD panel becomes a standard DVI monitor, and is connectible to anything. That is the ultimate goal for me.

I've just changed jobs (going from Mac Pro to unibody MacBook Pro sucks), and now have a lot more access to electrical engineers and circuit guys! Hopefully we can move forward on this soon here. Once I'm done moving to the new house, I'll have room and time to dedicate to this project. My electrical tools and spare panels and inverters have been packed for a month now...

[MisterDNA]

I should mention that I haven't left or forgotten this project. I've just been too busy and then too sick to do anything with it, but I have my jerry-rig DVI cable and it's all down to electrical now.

I won't be able to continue my work until the end of the month as I get knocked out for surgery on the 12th and then, if I survive, will be down for about two weeks.

With the recent refresh of the Mac Mini, this is even more intriguing to me.

[billib]

I'm not an Mac expert so please forgive me!
Wouldn't it be easier/cheaper to buy an inexpensive LCD monitor from NewEgg or TigerDirect, then remove the LCD panel from the monitor along with any electronics? Swap out the iMac display and components and connect the new VGA/DVI (?) cable the Mac mini you've hidden inside of the iMac base or connect it to an external Mac. Wouldn't this be quicker/easier to do than risk getting the pin out wrong on a hack of the original components and frying something? Also the LCD spec's are not great and the resolution is a tiny bit on the low side on the iMac. A new inexpensive LCD monitor can easily better it.
I have a 20" iMac and a hacked Mac mini with a 2.33 GHz Core2Duo Processor so I would like to blend the two eventually. I must say I'm not sweating the LCD hack but I am stumped on making a DVD w/tray work with the mini when its shoehorned into its new home. How will they fit? How will they connect? How will they work together?
I think the LCD hack will be (relatively) easy. Its the DVD that will be hard. NO?
Check out my Mac mini hack: http://www.flickr.com/photos/billibusa/

[newspimp]

I'm not an Mac expert so please forgive me!
Wouldn't it be easier/cheaper to buy an inexpensive LCD monitor from NewEgg or TigerDirect, then remove the LCD panel from the monitor along with any electronics? Swap out the iMac display and components and connect the new VGA/DVI (?) cable the Mac mini you've hidden inside of the iMac base or connect it to an external Mac. Wouldn't this be quicker/easier to do than risk getting the pin out wrong on a hack of the original components and frying something?


Well, yes, in some ways it may be easier to swap out the LCD panel for one from a standalone monitor. But, the point of this is to make good use of the perfectly functioning LCD in the iMac G4 :)



Also the LCD spec's are not great and the resolution is a tiny bit on the low side on the iMac. A new inexpensive LCD monitor can easily better it.

Personally, I'd disagree on this point. At least on the 20" models, the resolution is 1680x1050, which is still quite high (my 21.6" Samsung is the same resolution) and the panel is an S-IPS panel, which is VASTLY better quality than the TN panels in most of the cheap monitors available these days.


I have a 20" iMac and a hacked Mac mini with a 2.33 GHz Core2Duo Processor so I would like to blend the two eventually. I must say I'm not sweating the LCD hack but I am stumped on making a DVD w/tray work with the mini when its shoehorned into its new home. How will they fit? How will they connect? How will they work together?
I think the LCD hack will be (relatively) easy. Its the DVD that will be hard. NO?
Check out my Mac mini hack: http://www.flickr.com/photos/billibusa/

What I would do, is fill in the tray and cut a slot for the slot loading Mac Mini dvd drive and use that. At least, that's what I plan to do :)

MisterDNA, good luck with the surgery and I certainly hope you feel better.

[billib]

Newspimp you make some GREAT points about the iMac display that can't be ignored.
However, 20" LCD monitors can be picked up on sale around XMas time. I saw a few this past Christmas selling around $100 give or take a few bucks. I would be more inclined to hack that to pieces as opposed to chopping up a perfectly good iMac.
If you look at my mini hack on Flickr: http://www.flickr.com/photos/billibusa/

everything is easily reversible. I would like to make the iMac hack reversible also.
As far as accessing the mini's drive inside an iMac I've thought of gluing small hinges to the DVD drive COVER. then when you need to access the drive you would flip up the COVER.
You have made some great suggestions though, food for thought.
Thank you.

[Clive At Five]

I must say I'm not sweating the LCD hack but I am stumped on making a DVD w/tray work with the mini when its shoehorned into its new home. How will they fit? How will they connect? How will they work together?
I think the LCD hack will be (relatively) easy. Its the DVD that will be hard. NO?

Nah... Not with this handy trinket: JAE50 Cable (http://paul.thejennis.com/JAE50/About.html). Little pricey, but I'm using one in my G4 Cube/Atom mod (http://cliveatfive.xanga.com/tags/g4cube/) and it works like a dream... (with a Mac Mini slot-loader, even!)

[billib]

Clive I've been surfing the web for months looking for that connector. I'm sure many people have been looking for years. The best I could do was find a hacked up cable from an unreliable source. You are a miracle worker. Or maybe its the guy who came up with the cable......no wait its both. THANK YOU, THANK YOU, THANK YOU!!!!!!!!! I ordered one right away.
While miracles do happen maybe someone can come up with a "duel" connector cable because in the mini its dual channel and can support Two DVD's on that channel or a DVD and an HD. I can dream.
This has turned out to be a wonderful thread.

[Clive At Five]

Clive I've been surfing the web for months looking for that connector. I'm sure many people have been looking for years. The best I could do was find a hacked up cable from an unreliable source. You are a miracle worker. Or maybe its the guy who came up with the cable......no wait its both. THANK YOU, THANK YOU, THANK YOU!!!!!!!!! I ordered one right away.
While miracles do happen maybe someone can come up with a "duel" connector cable because in the mini its dual channel and can support Two DVD's on that channel or a DVD and an HD. I can dream.
This has turned out to be a wonderful thread.

Well, you're welcome. I have to confess, it is my own product. I don't like plugging myself so I only do so when someone has asked point-blank for what I offer.

That being said, I can console myself a little by plugging someone else's product as a possible solution for your "dual JAE 50" needs:

I would recommend using a female JAE-50 to IDE 44-pin. (I know a guy in Hong Kong who sells these. PM me if you want his contact info.) A couple of the leads require flipping but my same guy sells a modified IDE cable that does this too, so a lot of the work could already be done for you.

Anyway, from here, you could use a dual-socketed IDE cable. You can either convert back into JAE 50 using the very common IDE --> JAE 50 male adapter, or just use PATA drives.

The only difficulty of using his method is that I think you have to pull power for the drives from somewhere else unless you use slimline drives, which will require converting back into JAE, so there's a lot of adapters involved... it's definitely not pretty.

I'll ponder a JAE solution, but I can't promise anything. Doing the one "simple" cable was a nightmare in itself, I'm not too eager to pursue any new "inventions" for a while...

If you're interested in doing it on your own, I'll certainly give you the contact info for my manufacturer. Be forewarned though... It won't be cheap...

-Clive

[PatMcRotch]

Has anyone looked into just putting in a mini-itx intel board? I know everyone is trying very hard to get the existing screens to work with another Mac, but if the connection is essentially DVI (is it?) would it not just be easier to hook it to the DVI on the mini-ITX board and make a nice little hackintosh?

I'm just not wanting to go and buy a Mac Mini to gut and put in poor Marvin. I would rather buy the parts for a PC and piece it all together. I know it would require some hacking, slashing and maybe some soldering. I would rather to that to some bare-bones parts that to a new working Mini.

[dmmcintyre3]

Could you use a nvidia mini and a desktop CD drive and HD inside?

The dissasimbled LCD inside is a good idea. Does anybody know where you can buy a iMac G4 Case?

[Shake 'n' Bake]

Could you use a nvidia mini and a desktop CD drive and HD inside?

The dissasimbled LCD inside is a good idea. Does anybody know where you can buy a iMac G4 Case?

Just buy a broken iMac G4 off eBay.

[OrangeSVTguy]

Could you use a nvidia mini and a desktop CD drive and HD inside?

The dissasimbled LCD inside is a good idea. Does anybody know where you can buy a iMac G4 Case?

Was looking at this yesterday, http://cgi.ebay.com/Apple-Mac-iMac-20-G4-LCD-AND-BASE-COMPLETE_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a4Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a1Q7c 293Q3a1Q7c294Q3a200QQ_trksidZp3286Q2ec0Q2em14QQhashZitem29fe2cf4ccQQitemZ180358018252QQptZAppleQ5fDe sktopsQQsalenotsupported. Not a bad option if you ask me.

Just buy a cheapie 20" LCD monitor to swap in there and sell off the existing iMac's 20" LCD to offset the costs.

I thought I remember hearing though if you are going to replace the iMac's LCD with another monitor, routing the cables through then neck is either impossible or a nightmare because of the clearances. Either way, Good luck!

[dmmcintyre3]

With the 2009 Mac Minis: they have SATA CD drives. Could you just hook a desktop tray load CD drive up to the SATA connector on the logic board? Would the mini power it?

[edwlarkey]

Has anyone looked into just putting in a mini-itx intel board? I know everyone is trying very hard to get the existing screens to work with another Mac, but if the connection is essentially DVI (is it?) would it not just be easier to hook it to the DVI on the mini-ITX board and make a nice little hackintosh?

I'm just not wanting to go and buy a Mac Mini to gut and put in poor Marvin. I would rather buy the parts for a PC and piece it all together. I know it would require some hacking, slashing and maybe some soldering. I would rather to that to some bare-bones parts that to a new working Mini.

Hey I'm with you. This is exactly what I want to do. But if someone could answer a few questions I have that would be awesome.

1) I need to find a new motherboard that will fit into the round bottom. Think square inside a circle (because do they really make round ones?). We don't need to worry about the connections to the ports in the enclosure. Those can be figured out later.

1a) I would like to use the original or other optical drive in the same harness that the original came in. So the board would need to not be too high as to interfere with that. (Nice, but not absolutely necessary).

2) Is there any physical way to use that black cord coming from the display with any other board/graphics unit?

I have a 15" flat panel iMac. I think it is the original flat panel ones.

Thanks a lot,
edwlarkey

[newspimp]

Part of what we were doing on the previous two pages was scoping and tagging what each of the traces on the black video feed wire and power leads going through the metal stalk and into the LCD were.

I've changed jobs recently, into one where free time really doesn't exist and my supply of 20"G4 iMacs to work on is considerably less (relegated to my own parts one and my wife's working one). In addition, I've been in the fun fun fun process of buying and moving into a new house, also relegating many of my tools and parts to bins for moving.

I know MisterDNA has also had some things to occupy his time recently as well.

What we 99% know now is that the back, flat-blade connector going into the stalk is DVI signal compatible and that the displays work with a DVI signal. Powering the inverter and levelling the backlight signal are the next hurdles to making it so that any DVI signal from any type of computer will work. I'll personally probably be running a miniITX setup in my parts chassis.

As far as doing it with the factory DVD drive and hard drive carrier in place; that shouldn't be a problem. The chassis is setup for a conventional 3.5" HDD and 5.25" optical drive. Running SATA cables rather than IDE and power shouldn't pose any real problem, and the only problem you'd likely have is fitment of the optical drive, as the iMac G4 used ones that were slightly shorter than most so they could fit in the round shell. All you'll have to do is remove the front face plate from the optical drive, and it'll work perfectly with the fold-down cover.

[yourdogsmom]

Okay, so I've read this thread all the way through I think, and it's become apparent to me that it requires a lot of technical skill to use the current LCD panel in the iMac G4, and a lot of effort generally.

I have a Mac mini, and an iMac G4 15", and would like to put the mini inside the G4. I intend to buy a new LCD panel to replace that of the Mac mini, can somebody advise me as to the particular display I need that will allow me to plug the LDC panel directly into the Mac mini.

I think I can handle the rest of the job, it's just that I really have no idea what type of display I need to use.

Thanks.

[galvax]

hi, i was reading about how to use toy iMac G4 LCD screen and i have to say that i will love to do that myself!. Since my iMac G4 LCD screen is broken, i have to go with the LCD replacement idea for my 17" iMac G4, so my question is, Has anyone been able to do such thing? if so, could you please tell me how did you do it and what materials did you use?, also some pictures would be helpful too.

Thanks!!

[Calistoga]

Hi @ all. I rush throught this threat and will ask you if anyone was successfull with change innards of iMac with mac mini innards?
I´ve owned a iMac 20" and would like to change the innards to the newest mac mini. Could anyone post some pictures or send them to me, were the changed iMac is visible.

Thanks

PS: Sorry for my bad english...

[yourdogsmom]

I tried and failed.

I bought a broken iMac G4 off eBay a couple of months ago, with the intention on replacing the screen with a brand new monitor.

I dismantled the machine, and ran into multiple problems:

99% of standalone monitors have an inbuilt power unit, meaning they won't fit in the shell.

If I were to replace the screen with a new monitor, I would have to thread both a power cable and a VGA/DVI cable down the stem. This is difficult enough as it is, but all of the tools used to dismantle the stem that were around are no longer for sale.

The cables will not fit through the thin hole at the back of the screen housing, so you would need to splice the cables, possibly losing picture quality.

All of the ports in the mini are soldered to the back of the shell, so the USB, ethernet, power etc. don't align.

The disc drive is different, one is a sliding drive, the mini is slot-loading. I found that without the case on the mini, the discs literally fly out when ejected.

The stem needs the weight of the monitor to work, so if you get a screen too heavy or light, the screen will not stay when you put it.


Of course, if you could find a way to use the current LCD with the mini, so many of these problems would be overcome, but going by this thread, that's by no means easy.

If you were to use a standalone monitor, you're taking on a lot of work. I really wanted to try this, but the only 15" monitor I could find that was by any means 'slim' was discontinued by Xerox when I tried to buy it.

Shame, now I need to work out what to do with this pretty iMac shell..

[Dodo-v]

http://www.systemation-inc.com/manuals/ADP-103Manual.pdf I found that.

I'm hopefull ! good luck

[jberg44]

I did a similar mod replacing the 20 inch native monitor with an apple cinema display. Originally I had tried to use the existing screen and a tmds lcd controller using the native wires in the neck, but the stripped wires were extremely hard to solder (thin as a hair). So I gave up on running the wires through the neck. So it has the one wire from the apple cinema display coming out the back.
I wanted to use this as a second monitor so did not try to put a mac mini is the base. Although the fit may be tight with the faraday cage in there. Instead I put a blu-ray drive in the base to use as an external blu-ray player. Its on a machine running Windows 7RC.

[OrangeSVTguy]

I did a similar mod replacing the 20 inch native monitor with an apple cinema display. Originally I had tried to use the existing screen and a tmds lcd controller using the native wires in the neck, but the stripped wires were extremely hard to solder (thin as a hair). So I gave up on running the wires through the neck. So it has the one wire from the apple cinema display coming out the back.
I wanted to use this as a second monitor so did not try to put a mac mini is the base. Although the fit may be tight with the faraday cage in there. Instead I put a blu-ray drive in the base to use as an external blu-ray player. Its on a machine running Windows 7RC.

Looks pretty good. You should post of some pictures of the "build" process.

[MacOdyssey]

I've been fallowing this forum and dreaming about my own Mini powered iMac G4 on and off for a few years now. I periodically go on crazed rampages searching the internet for hours, looking for somebody who's done it, but have yet to find a success story.

So in spite of this native reinforcement, or maybe because of it, I have decided to do it and am determined not to stop until I have it working and ready to go. I'm going to be documenting the whole process on my blog (http://thegreatmod.blogspot.com/) so if you're at all interested, I hope that you'll fallow my progress and contribute any help or advice you might have for me.

http://thegreatmod.blogspot.com/

[OrangeSVTguy]

I've been fallowing this forum and dreaming about my own Mini powered iMac G4 on and off for a few years now. I periodically go on crazed rampages searching the internet for hours, looking for somebody who's done it, but have yet to find a success story.

So in spite of this native reinforcement, or maybe because of it, I have decided to do it and am determined not to stop until I have it working and ready to go. I'm going to be documenting the whole process on my blog (http://thegreatmod.blogspot.com/) so if you're at all interested, I hope that you'll fallow my progress and contribute any help or advice you might have for me.

http://thegreatmod.blogspot.com/

Great! I'll be keeping on eye on it. If you could, be sure to put major updates here for everyone that doesn't follow your blog. Good luck!

I'd would certainly do this if I had the money but I do have the skills. I'm sure I could even shove a MBP 17" into an iMac G4 shell :D and make it look good too ;)

[jberg44]

http://www.youtube.com/watch?v=PgISUgKtHCA

Putting a mac mini in the base is possible, but you will have to open up your mini or modify the faraday cage inside the imac g4 (its thick metal) for it to fit.

If you want to use the existing TMDS lcd you will need a TMDS controller
this is the only one i've been able to find:

http://agilentpixel.com/product.php?id_product=76

It does work with the 17" panel (LM171W02 A4) and it is possible (although difficult) to change the pin layout and use the existing wires in the neck. However, I was not able to get the existing inverter to work with it. Because there is no room for other inverters in the monitor case, it would have to be mounted on the back of the monitor.

For me, the solder of the TMDS cable was unstable and kept breaking (there are 16 wires - and they are very thin when stripped). My solution was to replace the whole monitor. Initially I tried using an apple cinema display, but it was too heavy for tilting. I ended up getting an LG monitor, putting it into the 20 inch housing and making a shelf on the back for the inverter, touch controller, and lcd controller. I've included pics of the shelf, which is currently temporary, until I decide what to make the final version out of (maybe plexiglass) on the back.

I also had bought a 17 inch hp monitor to create a 17 inch version, but I actually liked the look of the monitor so decided to paint the base black. It has a resistive touch screen.

[wesrk]

very awesome, jberg44
I saw the youtube video and besides the part where you tilt the camera, it looks pretty good my friend, nice job.
I'm also checking out MacOdyssey's blog. I'll be following it.

[jberg44]

very awesome, jberg44
I saw the youtube video and besides the part where you tilt the camera, it looks pretty good my friend, nice job.
I'm also checking out MacOdyssey's blog. I'll be following it.

Yea I know tilting the camera was stupid, i did another video with the camera not turned on its side:

http://www.youtube.com/watch?v=JV1mQ1r3SpY

MacOdysssey I saw your blog and wish you well. To warn you there are some problems with a desktop lcd monitor. The original panel on the 17 inch is a laptop lcd panel, most desktop lcd panels are heavier. This becomes a problem with the 17 inch arm, if you go over weight it will not tilt up or worse even fall all the way down. The 20 inch arm tends to be more forgiving if you go over the 11lb weight of the normal regular 20 inch monitor.

Also, the problem your gonna run into is the inverter. You will either need a custom inverter or need to figure out how to use the existing inverter, its one of a kind and the only inverter that will fit into the 3/4" case. Remember the wires connecting the inverter to the backlight can not be lengthened.

Good luck to you!

http://dremmeljunkie.blogspot.com/

[MacOdyssey]

Hey, jberg44, thanks for the well wishing and advice. A few questions though. On your blog, you mention you got the original speakers to work out. Could you elaborate on how you managed this?

Also, I appreciate the heads up on the potential problems with the weight of the display. What I did was actually replace the LCD glass (http://thegreatmod.blogspot.com/2009/11/monitor-replacement-renaissance.html) itself so the housing and everything is exactly the same. If worse comes to worse, when I had the neck open, I saw what looked like a tension adjustment so I'm thinking I could just adjust that.

To solve the inverter issue, I've found that lengthening the cables shouldn't cause dimming so I'm going to house the inverter that came with my monitor in the base of the iMac and use the cable that apple used for their custom inverter to connect it to the backlights.

I must say it makes me a little sad to see Windows 7 on that iMac. But the touchscreen is pretty awesome so I guess that makes up for it.

Dave
http://thegreatmod.blogspot.com

[jberg44]

Hey MacOdyssey: very smart to replace only the lcd glass and I'm glad youre not having any loss of power to the backlights. Good luck with the soldering I know how horrible those wires are. I saw how you cut the ends off, I may have an extra intact 17 inch neck - let me know if you feel like the solder is unstable and would like me to try to dig it up.

Similar to the LCD controller being on the mobo, the amp for the speakers is also on the mobo. So you could either build your own amp or buy a compatible amp. The only two with a minijack that I know of are the iFire (expensive) - needs a firewire port or the griffin powerwave adapter. While a sealed box will usually run $100 on ebay, you do not need the speaker wires or cd so you can get it a used one for considerably cheaper. I used the powerwave, its small, can fit in the base, and uses USB.

The machine its hooked up to is a hackintosh, I just wanted to play around with the windows 7 touch features :)

[MacOdyssey]

Wow jberg44, that's really generous of you to offer. I did have one of the wires break, but I think I'll be able to fix it. Other than that though, my soldering of the neck cables seems to be successful. Again, thanks for the offer though.

I knew about the iFire and have ebay set up to send me an email every time a somebody posts one, but like you said, they go for way over $100. I've looked around online for the Griffin PowerWave but haven't been able to find it for sale anywhere. Any ideas on that?

I would also love to build my own amp. I have no experience in the area but am confident I could find a good tutorial online. What are the specs it would need though? Do you know the power requirements of the Apple ProSpeakers?

[jberg44]

They are 10W speakers, but can handle up to 18W. I got a used powerwave for $50 on ebay, that was a long time ago though. The cheapest and easiest solution may be to buy a cheap pair of 10W-15W powered USB speakers and use the amp in them. You'd end up having to cut and splice the 2.5mm jack, but if you make your own amp you'd have to do that anyway.

[jindor]

http://www.youtube.com/watch?v=PgISUgKtHCA

Putting a mac mini in the base is possible, but you will have to open up your mini or modify the faraday cage inside the imac g4 (its thick metal) for it to fit.

If you want to use the existing TMDS lcd you will need a TMDS controller
this is the only one i've been able to find:

http://agilentpixel.com/product.php?id_product=76

It does work with the 17" panel (LM171W02 A4) and it is possible (although difficult) to change the pin layout and use the existing wires in the neck. However, I was not able to get the existing inverter to work with it. Because there is no room for other inverters in the monitor case, it would have to be mounted on the back of the monitor.

For me, the solder of the TMDS cable was unstable and kept breaking (there are 16 wires - and they are very thin when stripped). My solution was to replace the whole monitor. Initially I tried using an apple cinema display, but it was too heavy for tilting. I ended up getting an LG monitor, putting it into the 20 inch housing and making a shelf on the back for the inverter, touch controller, and lcd controller. I've included pics of the shelf, which is currently temporary, until I decide what to make the final version out of (maybe plexiglass) on the back.

I also had bought a 17 inch hp monitor to create a 17 inch version, but I actually liked the look of the monitor so decided to paint the base black. It has a resistive touch screen.

I'm also one of those who have been watching this thread for a long time, looking forward to someone making a breakthrough. It is so nice to see jberg44 made it even though it might not be exactly the way most of people would expect.

My wish is simple: I don't want sell off my beautiful 20" iMac G4, nor do I want to keep it in the corner of my room just gathering dusts; I want to use it everyday. I also wanted to be able to cram Mac mini innards into G4 but I kept lowering my expectation down to the point where I would be content if I could just use its screen part; I wouldn't mind taking all the guts of G4 if it's necessary; I wouldn't mind putting a Mac mini next to it, hooked up to iMac screen through external cable.

jberg44, I don't know much about all this hardware - but do you think it would be possible to keep iMac screen as-is, not replacing it with LG monitor like you did, and connect it to external Mac mini? You said there's not enough room for the extra TMDS controller. Would it be possible to put it inside G4 body if I took all the guts out?

[MacOdyssey]

My wish is simple: I don't want sell off my beautiful 20" iMac G4, nor do I want to keep it in the corner of my room just gathering dusts; I want to use it everyday. I also wanted to be able to cram Mac mini innards into G4 but I kept lowering my expectation down to the point where I would be content if I could just use its screen part; I wouldn't mind taking all the guts of G4 if it's necessary; I wouldn't mind putting a Mac mini next to it, hooked up to iMac screen through external cable.

Hey jindor, Your simple wish is exactly what I've been working on the past month. I've gone the rout of replacing the iMac's monitor with a new off the shelf unit. I almost done modding the screen and preparing to move on to the Mac mini part of the mod. I'm just troubleshooting some sort of weird issues with the video signal.

Check it out: http://thegreatmod.blogspot.com/

[jberg44]

Jindor - you can use the existing screen, you just need a TMDS controller like the one I mentioned earlier (only ever used it for the 17 inch panel, so I can not confirm that this controller will work for the 20 inch panel) just email them the panel number and they can program it for you. By switching 2 pins you can use the existing wires in the neck. And yes tyhe controller would easily fit in the base. The problem is with stability. The wires are very fragile - they break very easily. The TMDS controller and inverter are very small (I can show you pics) - if you don't mind putting it on the back of your monitor - you can very easily connect it with a separate cable to any DVI or VGA source you like.

Alternatively, if a TMDS controller is a problem, the 20 inch imac G5 uses the same exact panel, but with a standard LVDS connection. If you could find a iMac G5 panel you can always swap them and then use a standard LCD controller. This can quickly become very expensive, so be careful.

[jindor]

Hey jindor, Your simple wish is exactly what I've been working on the past month. I've gone the rout of replacing the iMac's monitor with a new off the shelf unit. I almost done modding the screen and preparing to move on to the Mac mini part of the mod. I'm just troubleshooting some sort of weird issues with the video signal.

Check it out: http://thegreatmod.blogspot.com/

MacOdyssey - thanks a lot! I wasn't knowledgeable enough to appreciate what you're doing. Please keep up good work and share the good news with us.

[jindor]

Jindor - you can use the existing screen, you just need a TMDS controller like the one I mentioned earlier (only ever used it for the 17 inch panel, so I can not confirm that this controller will work for the 20 inch panel) just email them the panel number and they can program it for you. By switching 2 pins you can use the existing wires in the neck. And yes tyhe controller would easily fit in the base. The problem is with stability. The wires are very fragile - they break very easily. The TMDS controller and inverter are very small (I can show you pics) - if you don't mind putting it on the back of your monitor - you can very easily connect it with a separate cable to any DVI or VGA source you like.

Alternatively, if a TMDS controller is a problem, the 20 inch imac G5 uses the same exact panel, but with a standard LVDS connection. If you could find a iMac G5 panel you can always swap them and then use a standard LCD controller. This can quickly become very expensive, so be careful.

Is the TMDS controller the one in the link http://agilentpixel.com/product.php?id_product=76 ? I wonder how big it actually is. Is it about the size of cigarette pack? If it worked with 20" screen maybe it would be the first thing I'd like to try out. I'm all thumb at this stuff. Could you kindly point me some info about how this module should be hooked up to the LCD screen? Clueless as to how to open up the screen part in the first place, and what those two pins you mentioned are...

Anyhow I'm so glad we finally have two guys shedding us lights! Thank you MacOdyssey and jberg44!

[newspimp]

Sorry I haven't been around much to contribute too much to the proceedings lately. I have been working on this project of mine (getting a standard 20" iMac screen, with existing base and cables and panel, to accept a standard DVI signal)

Good news was in that researching the panel and the DVI spec (which uses TMDS signalling) was that the TMDS input of the panel appears to be VERY DVI compliant. Except for one thing, which I haven't found a way around yet. DVI spec shows a TMDS signal at 165MHz. The IDTech panel accepts TMDS signalling at 117.5MHz.

Still haven't given up, but a new house, new job and the process of building an IT department and gearing up a manufacturing line has sucked my free time away like no other lately.