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

[GreyLotus]

Buy another Apple Keyboard with cable and if using a PC Keyboard look
at a real CMD Button (no WIN Button or SELECT Button)...

Hi, i highly doubt that this is the issue. It recognizes that I hold the alt key at startup, even on the wireless apple keyboard. I can‘t say for sure (because of black screen), but i assume that startup manager refuses any further keyboard input.

 

[gnommak]

I have news with my K3100M with white screen on iMac 27 2011.
I got it working!!!
After soldering resistor with lower resistance it just showing normal screen.
Also waiting for possible BIOS solution from @nikey22. I planning to test both of them.

And remember this solution is only for K3100M with Hynix memory that ends with BFR.
If you have other memory modules just skip this post. Thx!

Attaching all photos and video for my card to this post.

 

[KennyW]

After that, took out the HD5750, built in the GTX780M (Heatsink modification was necessary too).High Sierra boots up just fine, new GPU is recognized.
So, I'm repeating the process that I've successfully tested above. I hold alt during startup; As expected, the screen just stays black. After 20-30 seconds, the iMac should have successfully entered the startup manager utility.

Now from here, absolutely NOTHING happens. It's almost as if my keyboard had stopped working. It's just not doing anything. I don't get it to boot at all.

Did anybody experience this problem and was able to solve it?

I suspect you experience the Startup black screen of nVidia cards without a patched AppleGraphicsControl.kext as depicted in first post.

Further, haven't found anything regarding this, but can I update to Catalina using DosDude's patch without the flashed card? Or will I need the bootscreen for it? Meaning, can I possibly just skip the flashing, update to Catalina, and try the flashing from there?

Yes, you can actually install Catalina with your HD5750 without changing anything. The only important point is to disable automatic patching during the construction of the Catalina Install USB flash drive, and not to apply the Legacy Video Patch during Post-install. It is well documented in the first post. However, the iMac without a Metal GPU will run very slow in the Finder interface or anything concerning videos.

But then if you change the GPU, you won't see anything in internal display without a Mac vBIOS in your new nVidia GPU. However, some might get images in an external display. If your card can POST, the Linux system may be shown in the external display for you to perform the flashing.

I just wonder if High Sierra boots up just fine and your new GPU is recognized with internal display active, there should be no need to do any flashing ...

 

[nikey22]

K3100M - Hynix GDDR5 RAM Die Generation Variants​

There are at least 2 different K3100M Memory configurations floating out there for the Hynix MemoryVendorID

When I initially created the K3100M rom, I didn't realize that this existed. Then many people started to get the white screen failures. In my Post - Oct 18th, 2020 - I was able to finally create a working ROM for this type of failure.
<post 10,293>

The 2 varieties for the memory types are:
H5GQ2H24AFR - Hynix 1st Generation die - VDD 1.5V
H5GC2H24BFR - Hynix 2nd Generation die - VDD 1.35V

As pointed out by many here, the "BFR" based RAM chips are incompatible with the AFR rom. So I have created an entry in the original K3100M post to now include 2 ROMs - one for the H5GQ2H24AFR Ram chips and the H5GC2H24BFR Ram chips.

When you purchase a K3100M card, please look carefully at the RAM type and download the appropriate ROM.

Since doing this, @Schprecher discovered a hardware modification that could be made to the 2nd generation die cards that would allow them to interact with the 1st generation bios. This turns out to be a good discovery and was recently proven by @gnommak as mentioned above.

If you have a card that has Samsung or Eplida RAM chips, please send me your original BIOS rom and I'll see what I can do. But I don't think these exist.

So it appears we have 2 solutions to the K3100M white screen problem - hardware vs. software, both seem to work! Excellent work to all involved.

K3100M ROMs

 

[Ausdauersportler]

Hello everybody, thanks for the 450+ pages of helpful support.

I'm having the following issue when trying to flash:
Upgrading my iMac 2010 i7 2,93 GHz from a HD5750 to a GTX780M.
First thing I did was try out the "Xanderon" method with the HD5750 still inside; just to make sure everything with SSH is working and the usb drive gets recognized as a bootable drive. No worries, I did not go as far as to execute the flash exe 🙂 . Absolutely no issues here, Linux boots up from the stick just fine. I even took exact notes of how much time it needs to boot up, and when to hit the enter key, etc (knowing I will have to do this with a black screen later). SSH with ethernet connected to the iMac also works fine, even from the Termius app on my phone that's connected to the same router (root@iMacIP, pw: flash).

After that, took out the HD5750, built in the GTX780M (Heatsink modification was necessary too).High Sierra boots up just fine, new GPU is recognized.
So, I'm repeating the process that I've successfully tested above. I hold alt during startup; As expected, the screen just stays black. After 20-30 seconds, the iMac should have successfully entered the startup manager utility.

Now from here, absolutely NOTHING happens. It's almost as if my keyboard had stopped working. It's just not doing anything. I don't get it to boot at all.

I've already tried the following things:
- Unplug the internal SSD, so only the USB should be there to boot from -> no difference
- Unplug the USB to see if it would just boot from the internal SSD after hitting enter -> nothing happens
- Try different keyboards (wireless apple keyboard, as well as lenovo USB keyboard) -> same thing

Did anybody experience this problem and was able to solve it?

Further, haven't found anything regarding this, but can I update to Catalina using DosDude's patch without the flashed card? Or will I need the bootscreen for it? Meaning, can I possibly just skip the flashing, update to Catalina, and try the flashing from there?

Thanks in advance

Long text, confuse information. KISS is queen - keep it stupid simple!

Have you already flashed the new GPU? I assume no?
Did you try a PRAM reset after GPU change?
How could you boot into Sierra?
Without flashing no boot screen and using it blindly simply does not work in most cases.
First flash, then test on supported OS, then upgrade - first post is full of this information. If you haven't found you didn't search!

 

[Ausdauersportler]

I suspect you experience the Startup black screen of nVidia cards without a patched AppleGraphicsControl.kext as depicted in first post.



Yes, you can actually install Catalina with your HD5750 without changing anything. The only important point is to disable automatic patching during the construction of the Catalina Install USB flash drive, and not to apply the Legacy Video Patch during Post-install. It is well documented in the first post. However, the iMac without a Metal GPU will run very slow in the Finder interface or anything concerning videos.

But then if you change the GPU, you won't see anything in internal display without a Mac vBIOS in your new nVidia GPU. However, some might get images in an external display. If your card can POST, the Linux system may be shown in the external display for you to perform the flashing.

I just wonder if High Sierra boots up just fine and your new GPU is recognized with internal display active, there should be no need to do any flashing ...

This is a real bad advice!

A new user should always change only one thing at one time. Start with the GPU, then flash, then test, then upgrade the OS.

Every other plan ends up in chaos if the user does not know what he has to expect. Even worse with 2011 systems you get panics on each sleep attempt unless you patch, patch how should I do this?

 

[GreyLotus]

Long text, confuse information. KISS is queen - keep it stupid simple!

Have you already flashed the new GPU? I assume no?
Did you try a PRAM reset after GPU change?
How could you boot into Sierra?
Without flashing no boot screen and using it blindly simply does not work in most cases.
First flash, then test on supported OS, then upgrade - first post is full of this information. If you haven't found you didn't search!

Hi there, sorry for the confusion.

Flashing the GTX780 is precisely the problem.
On a normal boot (not holding any key), iMac with the newly built in GTX780 boots into HighSierra just fine.
When booting holding the alt key, screen stays black. I thought I should be able to blindly select the Linux USB Drive from the menu, but I guess I was wrong? Because whatever I do from here, it's not booting from the stick (I know because SSH won't connect).

So sorry if you feel like the problem has been discussed before. Of course I have read through this thread back and forth, but it seems noone has experienced something alike.

Obviously, I'm neither a technician nor a developper - not too familiar with things like Terminal etc.
I'd totally blame myself if I simply missed a necessary step?

 

[GreyLotus]

Yes, you can actually install Catalina with your HD5750 without changing anything. The only important point is to disable automatic patching during the construction of the Catalina Install USB flash drive, and not to apply the Legacy Video Patch during Post-install. It is well documented in the first post. However, the iMac without a Metal GPU will run very slow in the Finder interface or anything concerning videos.

But then if you change the GPU, you won't see anything in internal display without a Mac vBIOS in your new nVidia GPU. However, some might get images in an external display. If your card can POST, the Linux system may be shown in the external display for you to perform the flashing.

I just wonder if High Sierra boots up just fine and your new GPU is recognized with internal display active, there should be no need to do any flashing ...

Hi there, thanks for taking the time to help.
My question might have been not clear enough - I wonder if I can upgrade to Catalina with the new GTX780M, even though the card isn't flashed (so no bootscreen). Are the bootscreen/startup assistant needed during the Update (using DosDude's patch)?

 

[Ausdauersportler]

Hi there, sorry for the confusion.

Flashing the GTX780 is precisely the problem.
On a normal boot (not holding any key), iMac with the newly built in GTX780 boots into HighSierra just fine.
When booting holding the alt key, screen stays black. I thought I should be able to blindly select the Linux USB Drive from the menu, but I guess I was wrong? Because whatever I do from here, it's not booting from the stick (I know because SSH won't connect).

So sorry if you feel like the problem has been discussed before. Of course I have read through this thread back and forth, but it seems noone has experienced something alike.

Obviously, I'm neither a technician nor a developper - not too familiar with things like Terminal etc.
I'd totally blame myself if I simply missed a necessary step?

Disconnect the internal SSD and just plug in the USB, do not press any key on boot an wait. Obviously you are lucky enough to have a partly working BIOS an will be able to flash it using you own screen.

If nothing comes up on your screen than connect from remote as every other unlucky user would have to do.

AND PLEASE:
Add a signature with your hardware...we will loose track of your first post here and the signature stick with every post you make. Part of the first post, too.

 

[velvet_man]

Go to post #1 and read the open core section, it has the link to the most recent image. Try to use a different browser to come around the message may be another solution and there are a million tools to force downloads.

I was having the same issue, and it was difficult to find the explanations with so many posts in this thread. Maybe adding a line to the first post about the virus warning would help with this?

I think I've pieced most of it together now. I got Catalina Loader flashed to an SD card with the EFI folder copied over, and it booted! But, I still didn't have brightness control. I opened up the Catalina Loader configuration tool and installed the backlight fix kext and tried rebooting, but now it won't boot off the SD card at all. The progress bar will get to exactly half way, the screen will dim like the brightness control is starting to work, and then it will just hang there indefinitely.

I'm going to try redoing it all again, without the backlight fix (my screen is black longer than it used to be on startup, but it lights up after the chime so I don't think it's a problem). One thing I'm still not sure about is the config.plist. There are a bunch of them in there, including one that says NVIDIA-2011-27, which is what I would think I should use. But it says "just a sample, do NOT try loading". When I look at all of the config plist files, almost all of them say that, except the ones for AMD and Big Sur (I'm still on High Sierra at the moment). So which one should I be using? The last time I made a bootable SD card for Catalina Loader, I just copied the EFI folder over without changing anything since I had seen some YouTube videos that did that and seemed to work.

 

[Ausdauersportler]

I was having the same issue, and it was difficult to find the explanations with so many posts in this thread. Maybe adding a line to the first post about the virus warning would help with this?

I think I've pieced most of it together now. I got Catalina Loader flashed to an SD card with the EFI folder copied over, and it booted! But, I still didn't have brightness control. I opened up the Catalina Loader configuration tool and installed the backlight fix kext and tried rebooting, but now it won't boot off the SD card at all. The progress bar will get to exactly half way, the screen will dim like the brightness control is starting to work, and then it will just hang there indefinitely.

I'm going to try redoing it all again, without the backlight fix (my screen is black longer than it used to be on startup, but it lights up after the chime so I don't think it's a problem). One thing I'm still not sure about is the config.plist. There are a bunch of them in there, including one that says NVIDIA-2011-27, which is what I would think I should use. But it says "just a sample, do NOT try loading". When I look at all of the config plist files, almost all of them say that, except the ones for AMD and Big Sur (I'm still on High Sierra at the moment). So which one should I be using? The last time I made a bootable SD card for Catalina Loader, I just copied the EFI folder over without changing anything since I had seen some YouTube videos that did that and seemed to work.

Why should a add another line to the first post when most people have difficulties to understand the lines already there. It is a miracle how you ended up to get the original upload @Nick [D]vB made. We have already a plan, and a opencore section, and a post online describing what to do. More time I will not spent in it - the reading has to be done by the user.

All together this is not a Lego 6+ set, I will agree.

Read the first post, read the OpenCore section and read the post containing the latest image. And if you have seen some external YouTube videos why you are not asking the expert publishing it? Obviously you have more trust in the video than in the text written by the people developing and maintaining the project. This sounds ridiculous to me!

 

[FløH]

Hi guys, first of all, I'd like to thank all the forum members who contributed to this post. It's just epic what we've got going here.

So let me get straight to the point; yesterday I upgraded my 2010 21" iMac successfully (kind of).
I chucked in a K2100M and updated the VBIOS successfully. I was slightly worried that the TDP(55W) would be too high, but I'm not sure that it's having an influence on what I'm experiencing.

All went pretty well until I decided to upgrade to Catalina today, coming from High Sierra. I installed OpenCore on a separate boot partition and enabled the patches. All things considered, it's working okay but; I'm experiencing major lag in systemwide animations and weird artifacts on Forms which remind me of Windows XP back in the day.

As a sidenote, does anyone know why it takes so long for the computer to recognize the boot drive? I'm only getting the infamous startup noise after 10 seconds.

 

[Ausdauersportler]

Hi guys, first of all, I'd like to thank all the forum members who contributed to this post. It's just epic what we've got going here.

So let me get straight to the point; yesterday I upgraded my 2010 21" iMac successfully (kind of).
I chucked in a K2100M and updated the VBIOS successfully. I was slightly worried that the TDP(55W) would be too high, but I'm not sure that it's having an influence on what I'm experiencing.

All went pretty well until I decided to upgrade to Catalina today, coming from High Sierra. I installed OpenCore on a separate boot partition and enabled the patches. All things considered, it's working okay but; I'm experiencing major lag in systemwide animations and weird artifacts on Forms which remind me of Windows XP back in the day.

As a sidenote, does anyone know why it takes so long for the computer to recognize the boot drive? I'm only getting the infamous startup noise after 10 seconds.

- all these @Nick [D]vB BIOS versions have a timeout (somewhere mentioned) before switching on the screen
- possibly you missed the part about the legacy video patch with Catalina (post #1)
- try alt/option on boot and count the seconds...it will be there in less than 10 seconds
- if it is still a 10s lasting POST until you hear the chime it looks more like a hardware problem, one cable missing and some hardware, too?

Nevertheless, how often do you boot the system up a day and do you mind about some seconds spent there? Not spent, because booting happens in the dark...

 

[Misterhealy]

Hi All, Im new here and after reading the first post several times I've made the decision to upgrade my 2011 iMac with a K4100M. Ive made the purchase and waiting for the parts (hopefully before xmas!). Ive downloaded the ROM EXE for the K4100M and I'm about to decide how I'm going to flash it....

Am i correct in thinking that the iMac will boot into windows with the K4100M installed; from there i can flash it with NVFLASH? Alternatively, I have ordered the CH341a Clip Programmer, although I understand (from reading a previous post) that the K4100M might not come with the correct BIOS chip for the programmer?? Hopefully I'm wrong as this seems the most efficient method of flashing the BIOS. If neither of these two methods are viable I will do the USB flash thats recommended (I'm about to read that in-depth now).

I'm glad I'm not alone in thinking these iMacs have a few more years usage in them. I upgraded the HHD to an SSD last week and the improvement is sublime! Fresh install of High Sierra on the new SSD and I'm happy how its running. Now its time to focus on the faulty graphics card (yes it has ended up in the oven a number of times!). At least by taking it apart a few times I am aware that it has the 3-piped heatsink.

Ill keep you posted when the parts come in.

 

[GreyLotus]

Disconnect the internal SSD and just plug in the USB, do not press any key on boot an wait. Obviously you are lucky enough to have a partly working BIOS an will be able to flash it using you own screen.

If nothing comes up on your screen than connect from remote as every other unlucky user would have to do.

@Ausdauersportler many thanks - This did the trick and I was able to boot & use SSH to flash.

Hi guys, first of all, I'd like to thank all the forum members who contributed to this post. It's just epic what we've got going here.

So let me get straight to the point; yesterday I upgraded my 2010 21" iMac successfully (kind of).
I chucked in a K2100M and updated the VBIOS successfully. I was slightly worried that the TDP(55W) would be too high, but I'm not sure that it's having an influence on what I'm experiencing.

All went pretty well until I decided to upgrade to Catalina today, coming from High Sierra. I installed OpenCore on a separate boot partition and enabled the patches. All things considered, it's working okay but; I'm experiencing major lag in systemwide animations and weird artifacts on Forms which remind me of Windows XP back in the day.

As a sidenote, does anyone know why it takes so long for the computer to recognize the boot drive? I'm only getting the infamous startup noise after 10 seconds.

I am experiencing very similar problems here.

1. I installed theNvidia Patch from Post 1. I can boot with no Black Screen now & I can use an external monitor via MDP to HDMI connection. It did not solve the graphics glitch (very similar as in your video).

2. I have tried removing the video card patch by entering Recovery Mode and Running macOS Postinstall. I am shown an error message (1) when trying to unselect the patch & apply.

3. I modified the patcher with the instructions on Post 1 of this thread (replaced the plist file in the Content folder of the bootable disk) & re-installed Catalina. Unfortunately didn't solve the problem :-/ This resulted in "macOs Postinstall" no longer being in the utilities folder.

4. Booted in Recovery Mode Again & tried disabling the patch again -> same error message as in step2.

Any advice?

 

[Ausdauersportler]

@Ausdauersportler many thanks - This did the trick and I was able to boot & use SSH to flash.


I am experiencing very similar problems here.

1. I installed theNvidia Patch from Post 1. I can boot with no Black Screen now & I can use an external monitor via MDP to HDMI connection. It did not solve the graphics glitch (very similar as in your video).

2. I have tried removing the video card patch by entering Recovery Mode and Running macOS Postinstall. I am shown an error message (1) when trying to unselect the patch & apply.

3. I modified the patcher with the instructions on Post 1 of this thread (replaced the plist file in the Content folder of the bootable disk) & re-installed Catalina. Unfortunately didn't solve the problem :-/ This resulted in "macOs Postinstall" no longer being in the utilities folder.

4. Booted in Recovery Mode Again & tried disabling the patch again -> same error message as in step2.

Any advice?

Read the first post?
Add a signature!

 

[MacBurger31]

I tried the SSH Flash, but the flasher tells me the card's EPROM is not recognized.

Anyone recognise this, and maybe have a solution?

 

[GreyLotus]

Read the first post?
Add a signature!

I've read the first post at least a dozen times, I appreciate it a lot, but it's not as transparent as you might think it is. If you know what the issue could be here, I'm thankful for any help.

Added my signature as you wrote your post 🙂

 

[Ausdauersportler]

I've read the first post at least a dozen times, I appreciate it a lot, but it's not as transparent as you might think it is. If you know what the issue could be here, I'm thankful for any help.

Added my signature as you wrote your post 🙂

Good move with the signature. But I will no not copy and paste the solution here. You will have to check the specific section yourself. Obviously you already read it, how else did you know of the plist patching within the Catalina Installer. Your iMac, your puzzle, your success.

 

[ACwDC]

K3100M - Hynix GDDR5 RAM Die Generation Variants​

There are at least 2 different K3100M Memory configurations floating out there for the Hynix MemoryVendorID

When I initially created the K3100M rom, I didn't realize that this existed. Then many people started to get the white screen failures. In my Post - Oct 18th, 2020 - I was able to finally get a working ROM for this type of failure.
<post 10,293>

The 2 varieties for the memory types are:
H5GQ2H24AFR - Hynix 1st Generation die - VDD 1.5V
H5GC2H24BFR - Hynix 2nd Generation die - VDD 1.35V

As pointed out by many here, the "BFR" based RAM chips are incompatible with the AFR rom. So I have created an entry in the original K3100M post to now include 2 ROMs - one for the H5GQ2H24AFR Ram chips and the H5GC2H24BFR Ram chips.

When you purchase a K3100M card, please look carefully at the RAM type and download the appropriate ROM.

Since doing this, @Schprecher discovered a hardware modification that could be made to the 2nd generation die cards that would allow them to interact with the 1st generation bios. This turns out to be a good discovery and was recently proven by @gnommak as mentioned above.

If you have a card that has Samsung or Eplida RAM chips, please send me your original BIOS rom and I'll see what I can do. But I don't think these exist.

So it appears we have 2 solutions to the K3100M white screen problem - hardware vs. software, both seem to work! Excellent work to all involved.

K3100M ROMs

Thanks nikey22 ... working great now. Much appreciated.
AC
BTW the VRAM chips on my K3100m card are labeled as H5GQ2H24BFR. HP Card with original BIOS of: 80.04.05.20.05 !

 

[KennyW]

@Ausdauersportler many thanks - This did the trick and I was able to boot & use SSH to flash.


I am experiencing very similar problems here.

1. I installed theNvidia Patch from Post 1. I can boot with no Black Screen now & I can use an external monitor via MDP to HDMI connection. It did not solve the graphics glitch (very similar as in your video).

2. I have tried removing the video card patch by entering Recovery Mode and Running macOS Postinstall. I am shown an error message (1) when trying to unselect the patch & apply.

3. I modified the patcher with the instructions on Post 1 of this thread (replaced the plist file in the Content folder of the bootable disk) & re-installed Catalina. Unfortunately didn't solve the problem :-/ This resulted in "macOs Postinstall" no longer being in the utilities folder.

4. Booted in Recovery Mode Again & tried disabling the patch again -> same error message as in step2.

Any advice?

Since you have already got your new GPU flashed and working, I would suggest you wipe the newly installed Catalina and started from a fresh install. I am not sure whether a re-install over an old install would clear up the mess of Legacy Video Patch or not. There is a post on how to revert from an already applied Legacy Video Patch but it is a relatively complicated process. Just do a clean fresh install again would be simpler.

I suppose you are using DosDude1's Catalina Patcher for installation. The important point is to disable autopatch in the menu during preparing the USB Flash Drive. After installation, don't apply the Legacy Video Patch. But if you have followed Ausdauersportler 's advice in patching the plist of the Flash Drive, that should be ok. Everything is in the first post. I got a similar iMac 2010 27" though I used the AMD GPUs, but the process would be very similar. So, I talked from my own limited experience. My advice won't be as professional as our developers here. Just newbie to newbie in sharing. 🙂

 

[KennyW]

I tried the SSH Flash, but the flasher tells me the card's EPROM is not recognized.

Anyone recognise this, and maybe have a solution?

If your nvflash can't recognise the BIOS chip, there is not much more we can do. Perhaps you can take a photo of the chip & search the chip identity in the web to understand it more. Often they are WSON type EEPROM that is not amenable to the alternative clip method of flashing. Then you either have to return it or change the BIOS chip yourself to a recognisable one to nvflash if you are skillful enough.

 

[MacBurger31]

As I was looking for an 8-pin chip, there's a few possibilities on this card. frontside left of main chip, backside top center.
Need a microscope to read whats on them.

refitting an 8 pin chip is not that big of a deal, any outlets for that?

Thanks!

 

[Pascal Baillargeau]

As I was looking for an 8-pin chip, there's a few possibilities on this card. frontside left of main chip, backside top center.
Need a microscope to read whats on them.

refitting an 8 pin chip is not that big of a deal, any outlets for that?

Thanks!

Before doing surgery you could try to use the last linux nvflash version (5.660). Just in case...

 

[Ausdauersportler]

As I was looking for an 8-pin chip, there's a few possibilities on this card. frontside left of main chip, backside top center.
Need a microscope to read whats on them.

refitting an 8 pin chip is not that big of a deal, any outlets for that?

Thanks!

Bottom left is the WSON BIOS. There is a new nvflash5 available on techpowerup.com - download and install and check yourself. Possibly this new version knows this BIOS chip type. Just a guess.