iM 4,1-14,4 2011 iMac Graphics Card Upgrade

[Dilli]

LED3 will only light up, if a compatible EFI card is installed.
LED3 will now also light up with the latest nvidia EFI bootscreen mod from Nick.

When using stock card, and imac with no mods at all, LED3 will never light up..
just keep that in mind..
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the EFI bootscreen mod from Nick, has to be done with a CH341A programmer for example.
And needs external tools..

If you are not comfortable with this, than I suggest you leave everything stock, and just use your GTX765M withouth a bootscreen..

My card has reached my local delivery center. Should get it soon. So as per you have to install EFI boot screen mod. My only apprehensive is can it be done like a normal patch install.

I am posting two links. Is this what you are referring to.

Ebay
Ebay2
can the mod just be sent through usb. Could you provide link to the procedure

 

[Borak]

LED3 will only light up, if a compatible EFI card is installed.
LED3 will now also light up with the latest nvidia EFI bootscreen mod from Nick.

When using stock card, and imac with no mods at all, LED3 will never light up..
just keep that in mind..

Understand, FlorisVN.

I did a quick search here in the forum and found no one who put a GTX 660M in an iMac Mid 2011.

 

[FlorisVN]

That might be correct.
If you want a succes, it is simpel then I would highly recommend you stick with known compatible Nvidia or AMD cards !
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My card has reached my local delivery center. Should get it soon. So as per you have to install EFI boot screen mod. My only apprehensive is can it be done like a normal patch install.

I am posting two links. Is this what you are referring to.

Ebay
Ebay2
can the mod just be sent through usb. Could you provide link to the procedure

Hi, Ebay2 has the CH341A with all the eeprom clipper.
I would advise you to buy eBay 2 !
You need it at least for the bootrom patch of the iMac, you can also use it for your graphics card if you want..
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Catalina is working fine... it is just that you have no Recover Boot Screen...
With the new GC it is so much quicker and Catalina of corse..

recovery screen is indeed not working withouth a EFI bootscreen as far as I know and have tested in the past..

It's best to have a EFI bootscreen, which makes things much more easier..
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Is anyone available to check if the bootrom's I've dumped with romtool and flashrom to see if they are valid and that the modded ROM is ok?

Have been at it most of the day, even erasing the BIOS of the iMac completely and rewriting it with one of the dump's I made this morning. Nothing seems to work.

So either I'm the owner of a big paperweight or maybe someone can point out to me what I'm doing wrong and I'm the happy owner of a modded iMac.

Just to verify... flashrom syntax for flashing the bootrom is:
flashrom --programmer ch341a_spi -w bootrom_modded.bin

just send me your dumps, and I will try looking into it later this week..

 

[jborko]

@FlorisVN, on your comment:

"When using stock card, and imac with no mods at all, LED3 will never light up.."

I found this in the service manual:

LED #3

• Indicates that computer and video card are communicating. This LED will be ON when computer is communicating properly with video card. If LEDs 1 and 2 are ON and you heard the startup sound, but LED 3 is OFF, then the backup battery (on back of logic board) may need to be reseated, or the video card might be installed incorrectly or needs replacement.

On the topic of dump differences:

It's apparently normal for the romtool dumps to change, but I never trusted them due to that. I've done the dump/mod/flash but never used a CH341A programmer. If the software for the CH341A can verify the EEPROM ID before flashing, that would be a good start, as it would help to ensure proper communication with the chip. Likewise, I assume the software can verify the EEPROM after it programs it. which you should also do. If there was a bad connection when you copied the EEPROM with the CH341A, then your romtool backups would probably be usable.

You could look at both in a hex editor (or use diff) and see if the romtool and CH341A backups are significantly different, keeping in mind that there will be some differences, as that is apparently normal when dumping with romtool. If I were doing it, I'd probably use Hex Fiend, then open both a romtool dump and a CH341A dump at the same time, then use the comparison feature under the File menu, which allows you to do a side-by-side comparison.

Other than that, I'd suggest you try an NVRAM reset, if you haven't already, as well as a SMC reset (which I think removing the button battery and then putting it back in will do the job on an iMac).

You can send me your modified ROM if you wish and I will check over it for you. PM me, don't publish it publicly.

Which one can be trusted better for the dump: dosdude's romtool or the flahsrom with the CH341?
I made my dump with the romtool and now I am in doubts whether I can trust the MOD created from that dump.

 

[FlorisVN]

@FlorisVN, on your comment:


I found this in the service manual:


On the topic of dump differences:


Which one can be trusted better for the dump: dosdude's romtool or the flahsrom with the CH341?
I made my dump with the romtool and now I am in doubts whether I can trust the MOD created from that dump.

LED3 will only work, with original AMD card, or with Nicks EFI mod.
Nick has added LED logic board support, starting for Nvidia with vbios beta 2.

 

[jborko]

LED3 will only work, with original AMD card, or with Nicks EFI mod.
Nick has added LED logic board support, starting for Nvidia with vbios beta 2.

Right, so the stock card and stock logic board (without mods) should lit up LED3 (if all is working properly).

 

[FlorisVN]

Right, so the stock card and stock logic board (without mods) should lit up LED3 (if all is working properly).

that is correct.

 

[jborko]

After seeing the hijglander posts today, I made several more romtool dumps (on High Sierra) today just to test. I chose various chips in the romtool during the process (I still have not looked directly at the board to know what chip I have) and it appears (at least by the checksum) that the files are identical no matter what chip is chosen. Interesting is that when I compared today dumps with the dumps I made last week both with diff, shasum and then in a hex editor they appear different - file size is equal for all though.

The things I have done in the meantime is that I installed Windows (on an internal partition) and Catalina on an external drive. SIP is disabled on High Sierra where I made the dump, so I am really curious to understand why the romtool dumps are different? Any ideas?

 

[thinkfast76]

Hi all, can someone help me to find a vbios mod for m5950?

 

[StereoNewt]

Hi all, can someone help me to find a vbios mod for m5950?

i dont think theres a mod for that card

 

[Dilli]

@FlorisVN. Hi. Have ordered the 341chA Programmer kit on eBay. Meanwhile am preparing myself to update the vbios of GTX 765M which I should get it by this week.
I have few questions perhaps with your expertise you may answer.

1. Can I use windows 10 laptop to inject vbios file to the SOIC8 attached to graphic card GTX765M.
2. Can the clip on method be used for using Nick's mod for the iMac without installing graphic card , and is the power to be connected to the iMac. (Apparently there is no proper guideline on the forum that I could find on a step by step basis.
3. How is nflash to be used and since iMac is not working yet , is the procedure to be done using another mac.
4. Can 341a.exe windows file do all by connecting graphics card to SOIC8 and following screen details.
5. Can windows laptop be used to flash bios to iMac bios chip using clip on method. Is there any .bin file of Nick's mod vbios to load via windows.

If you can PM and send me all details and procedures I would be geared up till my hardware arrives to bring back a dead iMac 2011 27inch to life. Tks to all making this happen.

 

[jborko]

I know you asked Floris, but through reading the forum I think I can answer some of the questions as I am preparing to do the work myself these days (take it with some reserve).

1. Yes - CH341 programmer has Windows application that can be used - Nick's video on how to do this on Windows is posted in his post #2233
2. As far as I understand power has to be off - and the same method as for the 765m can be used on the bootrom chip.
3. You have to have a working Windows on the iMac that will be set as default operating system. Automatic login (without password or other pop-up windows that will stop booting) has to be enabled. Automatically started Remote Desktop Connection (Remote takeover solution) has to be installed (TeamViewer or something similar) that will be ready for connection from another computer. This assumes that you already have nvflash preinstalled on the windows copy and all the files ready for you to be installed. When the computer will boot, there is a chance there will be no display, but the Operating system should boot. Assuming you have network connection, you should be able to run remote takeover session and do the magic over that.
4. Yes - you should be able to alternatively flash the vbios using the CH341 and the clip from Windows - I will do this on Linux though.
5. As long as you are able to get the CH341a programmer to work with the windows application then yes. Check Nick's post here > post #2233.

I just got my second heatsink delivered, so I am going to attempt all of this in the next couple of days.

 

[Dilli]

I know you asked Floris, but through reading the forum I think I can answer some of the questions as I am preparing to do the work myself these days (take it with some reserve).

1. Yes - CH341 programmer has Windows application that can be used - Nick's video on how to do this on Windows is posted in his post #2233
2. As far as I understand power has to be off - and the same method as for the 765m can be used on the bootrom chip.
3. You have to have a working Windows on the iMac that will be set as default operating system. Automatic login (without password or other pop-up windows that will stop booting) has to be enabled. Automatically started Remote Desktop Connection (Remote takeover solution) has to be installed (TeamViewer or something similar) that will be ready for connection from another computer. This assumes that you already have nvflash preinstalled on the windows copy and all the files ready for you to be installed. When the computer will boot, there is a chance there will be no display, but the Operating system should boot. Assuming you have network connection, you should be able to run remote takeover session and do the magic over that.
4. Yes - you should be able to alternatively flash the vbios using the CH341 and the clip from Windows - I will do this on Linux though.
5. As long as you are able to get the CH341a programmer to work with the windows application then yes. Check Nick's post here > post #2233.

I just got my second heatsink delivered, so I am going to attempt all of this in the next couple of days.

Thanks you have giving me a good lesson. But if my iMac is dead as of now how can I run working windows on it. I need to do whatever for this process through another machine. I saw many videos on Youtube and the windows machine method looks very simple provided one has the right hardware.
Don't get me wrong I just feel my confusion is still there and I need to get some audio visual.
I request you to make a video once you proceed and put it on Youtube. It would really help.Tks again for your inputs👍

 

[jborko]

Right! So, then you have to use the programmer with the clip and another computer to flash the vbios from there. What you asked in question 4. Working vbios can be found in post #2233. Also if the card is from Dell Alienware there is a big chance that it will work out of the box without the flashing. In this way, you might get your mac operational albeit without the boot screen.

 

[Dilli]

@jborko tsk. Nicks mod file does not have .bin file which normally is to be flashed using windows machine. Yes the card is Dell Alienware GTX765M. In fact i wanted to insert the bios so that few commands like alt
could work and things work better on long run. I have downloaded and save Nick;s modded bios for later use.
But do make a video if you can

 

[jborko]

Sorry, check this post #2616 (vbios rom files for GTX series are there). ROM format though.

 

[FlorisVN]

Sorry, check this post #2616 (vbios rom files for GTX series are there). ROM format though.

for Nvidia, please use beta 2 from Nick !

https://forums.macrumors.com/attachments/kepler-beta2-zip.861577/

 

[FlorisVN]

@FlorisVN. Hi. Have ordered the 341chA Programmer kit on eBay. Meanwhile am preparing myself to update the vbios of GTX 765M which I should get it by this week.
I have few questions perhaps with your expertise you may answer.

1. Can I use windows 10 laptop to inject vbios file to the SOIC8 attached to graphic card GTX765M.
2. Can the clip on method be used for using Nick's mod for the iMac without installing graphic card , and is the power to be connected to the iMac. (Apparently there is no proper guideline on the forum that I could find on a step by step basis.
3. How is nflash to be used and since iMac is not working yet , is the procedure to be done using another mac.
4. Can 341a.exe windows file do all by connecting graphics card to SOIC8 and following screen details.
5. Can windows laptop be used to flash bios to iMac bios chip using clip on method. Is there any .bin file of Nick's mod vbios to load via windows.

If you can PM and send me all details and procedures I would be geared up till my hardware arrives to bring back a dead iMac 2011 27inch to life. Tks to all making this happen.

I would advise you to use MacOS/Linux for flashing with a CH341 programmer.
Simply my experience with good software and drivers are not that great under Windows.
I've used MacOS on my Macbook Pro, and worked great no problems at all..

You can use your CH341 programmer to replace the vbios of your card, and apply the bootrom mod from Nick.
You can all do this using Windows if you want..

Alternative you can use nvflash, using bootcamp Windows.
If you put a compatible Dell/Alienware card inside your iMac, it will boot just fine into MacOS.
You can then for example use my Winclone image, or an winclone image of someone else, and restore bootcamp.

It's up to you how you want to mod it, I would say.

For the vbios and EFI mod files, they are all arround this topic.
And all your answers can also be found here many times within this topic.

Please read a little more next time I would say..

 

[TheFalChris]

I highly
recommended you to use K5 Pro special thermal pasta for your new MXM video card. !
Its the same kind of stuff Apple uses, see following links and video as example :

K5-PRO & K4-PRO Set

K5-PRO & K4-PRO are designed to replace the thermal pads and thermal pastes of any electronic device including iMac, Playstation, XBOX etc

www.computer-systems.gr

K5 PRO 30g (3X10g) Viscous Thermal Paste for Thermal Pad Replacement Liquid Thermal Pad

www.amazon.com

Thanks for the tip. I’ve picked several tubes up and tried applying it instead, but still no luck, unfortunately. The old card at least works, so I’ll pop that back in for the moment.

 

[Dilli]

I would advise you to use MacOS/Linux for flashing with a CH341 programmer.
Simply my experience with good software and drivers are not that great under Windows.
I've used MacOS on my Macbook Pro, and worked great no problems at all..

You can use your CH341 programmer to replace the vbios of your card, and apply the bootrom mod from Nick.
You can all do this using Windows if you want..

Alternative you can use nvflash, using bootcamp Windows.
If you put a compatible Dell/Alienware card inside your iMac, it will boot just fine into MacOS.
You can then for example use my Winclone image, or an winclone image of someone else, and restore bootcamp.

It's up to you how you want to mod it, I would say.

For the vbios and EFI mod files, they are all arround this topic.
And all your answers can also be found here many times within this topic.

Please read a little more next time I would say..

Ok. In fact I did the reading in page 106 and few more pages and your results too in discussion with Nick. Lot of it went over my head but like you said i will read more and try to get it right however if I get stuck i can always seek help in here right. Is the vbios to be applied both to graphic card bios chip as well as logic board bios chip.

 

[FlorisVN]

Ok. In fact I did the reading in page 106 and few more pages and your results too in discussion with Nick. Lot of it went over my head but like you said i will read more and try to get it right however if I get stuck i can always seek help in here right. Is the vbios to be applied both to graphic card bios chip as well as logic board bios chip.

happy reading !

the graphics card needs a new custom vbios flashed, and the bootrom from the iMac (bios chip), needs a patch aswell.
Both are provided here by Nick !

 

[PSILONCRAFT]

I have a Clevo GTX 860 with 4 GB vram does that have anything to say regarding thr vbios you tell me to use?

ok so I had to go the Raspberry pi way. I have connection to the bios chip it lists AS gd25q20(b) (256 kB, SPI) Did a backup called Flash.dat. When i try to write the recomended .rom file i Get error: image size doesn’t match the Flash chip size. Look at attached image. Need help

 

[PSILONCRAFT]

happy reading !

the graphics card needs a new custom vbios flashed, and the bootrom from the iMac (bios chip), needs a patch aswell.
Both are provided here by Nick !

so i have an issue. I use Flashrom on Raspberry pi/ Linux to connect with the bios chip. But Im confused since Flashrom makes a backup in .dat format. The custom bios is in .rom format and i Get an image error when i try upload the .rom file to the chip. Look at my latest post for image. Is there a way to convert the .rom file or are my Doing something wrong here?? https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/post-27969844

 

[highvoltage12v]

@Nick [D]vB
I ended up having to remove my 770M from my 21.5" iMac. The kernel panics were getting so bad the iMac was becoming unusable. To 100% target the issue down to the 770m I swapped the PSU from my 2010 iMac, Reinstalled my old i5-2400S, dropped down to 1 stick of ram, went back to 1 SSD and finally patched 87.0.0.0 and flashed it to my iMac. From what I have gathered from the kernel Panics, the 770m seems to drawing too much amperage on the 5V rail causing my SSD's to stop working and the iMac rebooting. Really unfortunate, at one point i really thought the issue was firmware related/APFS. but I haven't seen rebooting since installing the k2000m. The panics also happened a lot in Mojave, sometimes in Catalina and never in High Sierra. If you'd like to take a look at my iMac rom Dump PM me.

 

[FlorisVN]

@Nick [D]vB
I ended up having to remove my 770M from my 21.5" iMac. The kernel panics were getting so bad the iMac was becoming unusable. To 100% target the issue down to the 770m I swapped the PSU from my 2010 iMac, Reinstalled my old i5-2400S, dropped down to 1 stick of ram, went back to 1 SSD and finally patched 87.0.0.0 and flashed it to my iMac. From what I have gathered from the kernel Panics, the 770m seems to drawing too much amperage on the 5V rail causing my SSD's to stop working and the iMac rebooting. Really unfortunate, at one point i really thought the issue was firmware related/APFS. but I haven't seen rebooting since installing the k2000m. The panics also happened a lot in Mojave, sometimes in Catalina and never in High Sierra. If you'd like to take a look at my iMac rom Dump PM me.

i guess this confirms it for 21,5” iMacs.
Only use smaller low powered cards, like the compatible quadro cards..
This iMac was also not designed to run with bigger high end cards anyway.. 😉

A quadro rom for these cards for a efi bootscreen mod, would be great someday if made possible..