Ultimate (iMac) MXM efi rom/vbios thread...

[lion10]

550$ is really "beyond everything".

Well, welovemacs.com is probably one of the most expensive sources. I saw that card also on ebay for near the half price. However, out of my view also 250$ is clear too much...

According to the mentioned ALU iMac 2007-2008 Geforce 8800GS problems,- this Radeon HD 6970M is no solution because its fully incompatible.

iMac 2006-2008 has MXM 1Gen (First Generation), iMac from 2009 has MXM 2Gen (Second Generation). These two standards are completely incompatible.

[Rominator]

Som ebrave soul needs to work on this stuff.

So much potential.....

[kinheng]

@lion10

Dude, I read all your post and seems like you are the person who I can direct my question to
and any help would is MUCH MUCH appreciated.

I have an 24" alum. Imac 2008, and I believe suffer from GPU failure
I was wondering the symptoms provided below match what you have experienced / can confirm
before I spend $ to buy any parts and not able to fix the computer

Symptoms:
1. LED 1&2 lite up on logicboard when power button is pressed, LED 3 flash quickly. (GPU in place)
2. Was able to boot when GPU is not connected (of course nothing shows on screen)
3. system boots and got into OS and was able to remote control system when GPU was disconnected.

Any thing you can share is again Much Much appreciated (I loved the computer! but seems like GPU failure is inevitable and common)
do you have a extra working GPU for sale?
or any Recommendation for an replacement?

[aurejac]

Som ebrave soul needs to work on this stuff.

So much potential.....

Hi to everyone,

I'm new to this forum, but willing to do some work on the iMac MXM hack (Apple will stop to supply parts for this mac during september 2012).

So here are my guess, from what I know, and what I tried :

1-  the white, core2duo iMac 24" (iMac 6.1) uses either a Nvidia Geforce 7300GT (128MB) or 7600GT (256MB).

2 - Those originals apple GPU are both, plain regular MXMII form factor cards (41mm separated holes), with 1.3 or 2.0 specifications (this is not clear).

What follows is only for the 7600GT :
3 - the original card use GDDR3 ram (K4J52324QC-BC14 - 512Mbit chips)

4 - it has a regular 128KB eeprom (Atmel AT25F1024AN)

5 - It seems to be a desktop GPU, it has a 0391 device ID.
While booted with extensions off (the card was defective), "Zeus" software did told me the 7600Gt worked at 200.475 Mhz speed (with multiplier ?). I was able to get a dump of the apple rom.

6 - There seems to be hope for finding a replacement.

I found those cards to have a nearly same design than the original 7600GT :
http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=271010547585

Those cards have a design very closed to the iMac 6.1 7600GT cards :

• same chips, transistors, selfs, condensators, in the same place
• GPU is a G73M which seems to be the same as the G73 with different timings ? (do i make errors on this ?)
• they have a 128 KB eeprom which is great
  
• but they have a device ID 0x0398 and use DDRII.
  

I manage to make a try, and I bought and install this card in a defective 24" white iMac.

In fact, it fitted perfectly with the original heater.
So I did make a try : while it has of course shown no video in MacOS X, I managed to get working video on an external display with Bootcamp (I did not tried with onboard display, sorry...) :



I then did try to flash the firmware of the card with the iMac 7600GT firmware, and, to my surprise, it worked and guess what, I did have video on EFI boot...
Of course, it was scrambled video, but with using GDDR3 timings on DDR2, it did not surprised me :



So, where to go from this ?

It seems I'm not far from having a working replacement car for my iMac 24".

I have no knowledge at all on how to mod the EFI rom on this card, so that it work with DDR2, but I'm able to give some work, and to send my rom dump to anyone who want to make a try...

I have the iMac laying next to me, and I'm able to burn bootcamp CDroms with nvflash, and try any EFI rom that someone with the knowledges will be king enough to give me to try.

I will also, if all this works, be pleased to make a how-to...

[aurejac]

Hi,

here are links for the unpatched rom files :
 
Original iMac 6.1 7600GT rom file :
http://gilles.aurejac.free.fr/Nvidia7600gt/7600GT-imac61.rom

Tested Acer MXMII 7600Go card :
http://gilles.aurejac.free.fr/Nvidia7600gt/Acer.7600Go.256.061016.rom

thanks

gilles

[blacksheep]

Hi, I'll try to help a bit.

Here you are:
- original iMac ROM with DID changed to match Acer card
- hybrid Acer + iMac ROM with DID unchanged
- hybrid Acer + iMac ROM with DID changed

First one probably won't work any better than "clean one", because there's too much difference in specs between 7600GT and Go.

Keep in mind that I am not EFI guru or flash master. All I've done is alter DIDs and some copy/paste job. EFI in hybrid ROMs starts at that same offset as in original EFI ROM.

Test these ROMs on you own risk. Don't blame me for bricking your card.

Post results if you'll decide to test these ROMs

[aurejac]

Hi,

so, in two word :

• sadly no, none of the rom worked
• and yes, I have "bricked" the card 

I flashed the Go 7600 card with the first rom, but it made the same scambled display with EFI boot, (it also showed me scrambled display while taking control with apple remote desktop !) also the imac could sometimes not reset pram.

With the two others rom (hybrid) there were the same scambled video (but with a different pattern)
I was able to flash in blind mode under DOS but ended with no video at all

The good news is that I burned nothing (except the eeprom erased with unvalid rom), and except for the video card, the imac still works
And I'm still able to have access to the computer with remote desktop, either with OS X or Windows (bootcamp).

NVflash tells me that there is an "unconfigured display adapter found, device not accessible" and still see it as a 10DE,0398 GeForce Go 7600

I'm trying to flash it backward (i may try an utility like wflash, but not sure...)
If it doesn't work, I will unsolder the eeprom and solder another one.

Is it possible to build an hybrid rom with the same bios part as the original one from the PC (7600M)
And especially is it possible to mod the EFI part of the 7600GT with having core and memory frequency of the 7600M

I found on wikipedia that the Go 7600 has 450 Mhz core frequency

http://en.wikipedia.org/wiki/Comparison_of_Nvidia_graphics_processing_units


If nothing work, I'm willing to try other ways :

• first, unsolder the eeprom on the defective apple 7600GT, and solder it in place in the acer GO 7600, then try to flash it again
• if nothing works with the Go 7600, I may try ATI x1600, there are some MXM II cards to sell on ebay, and I can get the rom on a 20" iMac...

[blacksheep]

Hi,

so, in two word :

• sadly no, none of the rom worked
• and yes, I have "bricked" the card  

Sorry about that  

http://netkas.org/?p=1182 - netkas did post interesting alternative to chip desoldering, but you need to check if it would work for you.

NVflash tells me that there is an "unconfigured display adapter found, device not accessible" and still see it as a 10DE,0398 GeForce Go 7600

I've changed DID in BIOS part of the ROM and in EFI too. There must be another (tokenized?) instance of DID in PC or EFI part, or maybe it's hardwired.

Is it possible to build an hybrid rom with the same bios part as the original one from the PC (7600M)
And especially is it possible to mod the EFI part of the 7600GT with having core and memory frequency of the 7600M

I believe it is, but my skills are too weak to do that (so far at least), as it turned out. You need Rominator or netkas to take a look on these unmodified ROMs. From what I know, there's no need to modify clocks in EFI part, because all frequencies are read from BIOS part of the ROM.

Best of luck, and I'll be following this thread. If I'd discover anything - I'll let you know.

[aurejac]

Hi,

thanks for the answer. I was able to flash the card back with bootcamp, but still no video.
I will unmount it asap, and try to touch Netkas or roomie by email...

Also, I founded this :
<http://www.ebay.com/itm/MXM-7600GT-256MB-Video-Card-For-iMac-24-Model-Number-A1200--/180970130974?pt=PCC_Video_TV_Cards>

The auction states that it is a PC card flashed for mac... sound interesting !

[Rominator]

OK guys, I am interested in helping but you will need to understand some things.

First and foremost, i am greatly impressed that people are trying stuff on their own. I think too many people come by here demeaning a "step by step tutorial" for things they MIGHT be able to figure out themselves.

Please don't try to unsolder the EEPROM. It is SOOOO easy to lift a trace and that is ALOT harder to fix than a bad flash. Aside form Netkas' method you can also reprogram chips on the card using a programmer. If someone trying MXM work needs this done, PM me. You can send card to me and I will do this for a 6 pack of Stella and return shipping.

I would also like to take this opportunity to point out that the EBay auction you linked is from a guy who I am proud of for doing something new. In the past he blatantly BORROWED MacVidCards roms and sold them as his own. (look through his feedback, he actually sold cards that said "MacVidCards" on screen)

After getting a few of his items yanked by Ebay he has at least tried to do his own thing. We need MORE people trying to flash MXM cards and innovate instead of copy. So I applaud Foeul's efforts and hope that he will continue to work on this.

I feel fairly certain I could write this rom for you but I am going to give him a few days to come by and become the MXM guru. The cost and bother of flashing & testing MXM cards makes them a real headache. But I think that there would be HUGE demand for iMac folks to be able to upgrade their cards, even if just in the same family or one step up.

[aurejac]

Hi,

thanks a lot for your answer, and ok, deal for  the 6-pack  

It wouldn't have been a big mess to unsolder the eeprom, I already have done this tens of times for flashing Pc Sapphire Radeon 7000 cards with 128KB eeprom so that they work with PowerPC G4... (it was yeeears ago )

So, I did bought "macgraphicsfan" card, and now I have two cards :

- the Acer Go 7600 MXM 35G1P5310-10 that I have managed to flash back to original bios rom.
When I flash it back to its original bios rom, it works in Bootcamp, and, surely, doesn't work with MacOS (black display).
With EFI roms from 7600GT (and those from blacksheep), it displays a scambled video. I bet it is because of DDR2 timings (and also, I'm not sure to have save the good original bios rom...)

- the 7600Go card from ebay seller "macgraphicsfan" (i it the same guy you call "Foeul" ?).  
This one works nicely, and is based from a DDR3 MSI card.  
The only drawback is that it doesn't work at all with Bootcamp (it hangs at startup).
I will post installations photos in a separate post.

I have no will to post a copy of the firmware made by "macgraphicsfan", although I made a backup of it.
I know it is his work, and respect it.
I'm mostly willing to found a way to make Go7600 DDRII to work.

I have no hurry, because I have a first iMac 24" repaired with macgraphicsfan MXM MSI DDR3 card, and a second one which can wait...
And I can take some time to do some tests.

If you can help me to make the DDRII Acer card to work, It still would be very nice (and you would get a 6-pack   )

[aurejac]

Here are the pics for the installation of "macgraphicsfan" MXM card :

here is the postman...

what's inside ?

yes, an MXM card...

Time to so some unscrewing...

Get all of the cables of, they are fragiles

MLB and the acer MXM DDR2 card

"macgraphicsfan" MXM card back

and front

with ram thermal pads

no jealous, the copper heatsink get a thermal pad too...

home-made washers

back in place, don't forget to plug the thermal sensor cable

logic board back in the imac

it works !

[fouel]

Yes, it works.
Thanks for your updates.
Enjoy it.

[Rominator]

Yes, it works.
Thanks for your updates.
Enjoy it.

Hey there, fouel.

Congrats on creating a new card. Feels good creating something that didn't exist before, doesn't it?

BTW, I have a pretty good idea why the card won't work in Bootcamp. It is most likely a case of device id not matching from EFI and BIOS soft straps, or you didn't fix the BIOS checksum. It is fixable.

[eastfirst169]

Hi I am new to netkas.org and I was in the look out to do pc rom to imac efi rom cross-flash and saw this thread I've read through the entire thread but are there new updates any new updates regarding this project?

@aurejac could it be that the 7600Go you got on ebay doesn't have the latest efi.rom to support bootcamp? Do you have at least version 3022 in your 7600GT,

I have access to an Apple original 7600GT MXM but I won't have it until I get there over the weekend as far as I can remember, I know that card has version 3147 installed.