eMac 800Mhz -> 1.33GHz conversion

MrFX · Mar 7, 2005

Hello guys,

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

Now i'm installing X.3...

Not bad for 180 Euros.

So long.
MrFX

guylan · Mar 7, 2005

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

Ok here is a tidbit...

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

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

vga4life · Mar 7, 2005

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

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

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

-vga4life

lbodnar · Mar 7, 2005

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

On Gen2 board it works that way...

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

As you can see it involves nearly all available resources to simply power the thing on!
My solution is to just permanently ground DPO on the blindmate connector.

Same logic and signals apply to Gen1 board too.

lbodnar · Mar 7, 2005

Generation 1 (700/800MHz) downconverter board

Generation1 eMac downconverter board (DCB) pinout:

1,3 20V from analog board power supply. This is INPUT to DCB.
2 Gnd for 20V
4 Gnd sense for 20V
5 PRO - overvoltage signal (active high) output.
6 DCO - turns DCB on (active low) input
7,9 +3.3V
11 +2.5v
13 +2.5v sense
15,17,19 +5v
8,10,12,14,16,18,20 Gnd

If you want to replace DCB altogether, connect all Gnd together and provide permanent 5, 3.3 and 2.5v to logic board. 2.5v is pretty low current (DRAM) so linear regulator off 5 or 3.3v will do.

netjosh_granada · Mar 7, 2005

lbodnar said:
On Gen2 board it works that way...

Everything is warmed up by trickle 5V and standby 12V.

Power On button push sensed by PMU controller on logic board.

It sends message to a microcontroller on IVAD board (silver can) via two I2C wires on video connector. They are not VGA DDE data link and also used to control CRT brightness, geometry, etc.

IVAD microcontroller sends PWRON signal (high) to analog board.

Analog board inverts it and makes sure overvoltage signal (PRO) is OK (low)

Inverted (low) power on signal (DPO) is sent to logic board via blindmate connector.

It gets directly to downconverter and activates it.

the rest of the magic happens

As you can see it involves everything in simply powering the thing on!
My solution is to just permanently ground DPO on the blindmate connector.

Same logic and signals apply to Gen1 board too.

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

lbodnar · Mar 7, 2005

netjosh_granada said:
Do you mean that without IVAD, emac won't power up?

It will if you forcefully switch downconverter board on (by grounding DCO signal on blindmate connector.)

MrFX · Mar 7, 2005

Hello all,

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

This posting i'm writing with it

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

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

Bye.
MrFX

guylan · Mar 7, 2005

OK here is the Blind-Mate voltages

Ok here is the Blind-Mate connector updated

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

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

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

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

lbodnar · Mar 7, 2005

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

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

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

1. I was going to say that Gen2 and Gen3 boards look absolutely identical near the area around blindmate connector.

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

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

lbodnar · Mar 7, 2005

Gen1 700MHz blindmate connector

guylan said:

Ok here is the Blind-Mate connector updated

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

Code:

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

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

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

Looks like pin 11 is trickle 5V

MrFX · Mar 7, 2005

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

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

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

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

So long and sleep well.

MrFX

lbodnar · Mar 7, 2005

MrFX said:
I've shot the photo below to demonstrate, that it is working.
Now i'm looking forward for a little PSU and some other accessiores...

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

guylan · Mar 7, 2005

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

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

Looks like pin 11 is trickle 5V

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

madmaxmedia · Mar 7, 2005

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

Hi Leo,

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

Thanks,
Steve

lbodnar · Mar 7, 2005

Gen1 700MHz/800MHz pwned!

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

guylan · Mar 7, 2005

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

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

Blind-mate nearest CPU

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

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

lbodnar · Mar 8, 2005

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

Yes, of course! I know what to look for, I just can't see it from existing photos. I need an area around connector J11.

netjosh_granada · Mar 8, 2005

eMac Custom Cases - Ideas??

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

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

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

lbodnar · Mar 8, 2005

Power Supplies review

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

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

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

jspivack · Mar 8, 2005

and without DCB...?

Leo, Guylan

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

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

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

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

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

thanks

Jeff Spivack
Nantes, France

lbodnar · Mar 8, 2005

jspivack said:
So, let me see if I've got this straight...if I follow what Leo posted in comment #356 ("Generation1 eMac downconverter board (DCB) pinout:..."), then i should be able to boot my Gen1board
1) without DCB
2) and without analog board
3) and without the IVAD?
I would also have to ground pin 6 (DCO) on the DCB and power the HDD and CD-ROM separately. right?

Jeff, yes you should be able to, but you need to get 2.5v power from somewhere. I am not sure what does it power up but it is rather low current supply. I will try to experiment with some really cheap tricks like dropping 0.7-0.8v off 3.3v via a power diode or if not then build a quick LM317-based regulator.

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

MrFX · Mar 8, 2005

Hi all...

@Leo: i've uploaded a hi-res photo from the area around J11, tif-format, you can get it here.

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

So long,
MrFX

lbodnar · Mar 8, 2005

Gen1 700MHz/800MHz "headless" details

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

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

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

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

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

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

MrFX · Mar 8, 2005

Hello!

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

Best wishes,
MrFX

eMac 800Mhz -> 1.33GHz conversion

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