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

[The_Croupier]

hi there everyone! o got a problem with flashing my gtx680 tried al the methods i think
is says pcie board id mismatch...how can i fix this thing? thank you for your answears

Use the search function - does not match adapter -

 

[maccoops]

I use an m5100 with Ventura.
Works nicely. Only two problems. You lose sleep (so you need to deactivate it because the iMac does not wake up from sleep), and some times you may experience some graphical issues during boot and you would need to restart. But this does not happen often.

Following up... Thanks to posts like this one I decided to try a AMD M5100 in spite of the 1st post in the thread which gives a dire warning about using this and similar age AMD cards in 2011 iMacs - says PRAM must be reset every cold boot, do not use, etc...
The similarly priced Nvidia cards (like K2100M which I have installed) do not have metal support, and more recent Nvidia cards with metal are not economic for me. Furthermore there a numerous warnings in this thread about limited supportability for Nvidia cards with Ventura and beyond.
These AMD cards seem to have metal and are priced within reach... So I have given the AMD M5100 a try, and can report no issues so far with cold boot, sleep, wake etc. I did have to do a PRAM reset and I was very careful to follow the specific instructions for this card which are linked to from the first post.
I had to manually edit the config.plist as the GUI based process described there seems to be broken in the current releases of OCLP - and I consider myself lucky to have spotted that.
Anyway, just wanted to share a success with this seemingly good value for money card.
Thanks to the devs who have worked on this!

Edit: don't forget the shim!

 

[internetzel]

Following up... Thanks to posts like this one I decided to try a AMD M5100 in spite of the 1st post in the thread which gives a dire warning about using this and similar age AMD cards in 2011 iMacs - says PRAM must be reset every cold boot, do not use, etc...
The similarly priced Nvidia cards (like K2100M which I have installed) do not have metal support, and more recent Nvidia cards with metal are not economic for me. Furthermore there a numerous warnings in this thread about limited supportability for Nvidia cards with Ventura and beyone.
These AMD cards seem to have metal and are priced within reach... So I have given the AMD M5100 a try, and can report no issues so far with cold boot, sleep, wake etc. I did have to do a PRAM reset and I was very careful to follow the specific instructions for this card which are linked to from the first post.
I had to manually edit the config.plist as the GUI based process described there seems to be broken in the current releases of OCLP - and I consider myself lucky to have spotted that.
Anyway, just wanted to share a success with this seemingly good value for money card.
Thanks to the devs who have worked on this!

Experience has been that those earlier AMD cards can work for some time without a PRAM reset for every boot. But so far sooner or later the constantly needed PRAM resets did return.
So that is what is to be expected based on those experiences.
Please keep the thread updated about your experience over the coming months!

 

[Ausdauersportler]

iMac9,1 24" early 2009 EFI boot screen support (LVDS)

Recently I found a way to enable EFI boot screen on the iMac9,1 24" model. Instead of repeating the complete story and adding a new self similar post I added the information to my former post about LVDS support.

Additionally the tables and information on the first post of this thread have been updated to reflect the latest situation. Right now we have tested all Venus cards (M4000, M5100, W5170M, M6000) and Saturn cards (M6100, W6170M) successfully.

Please be aware of the fact that there is special EnableGop91 driver in the vBIOS necessary to enable the EFI screen on iMac9,1 - so you need to pick the prepared vBIOS versions with this driver from the GitHub repository. I have used speaking names for the vBIOS files - you cannot miss the EnableGop91 within in the file names.

The more recent GCN4 cards (WX4130, WX4150) will basically boot and run in older iMac9,1 and iMac10,1, but no LVDS and EFI vBIOS mod has been successfully testet so far with these cards.

All AMD cards need OCLP and the SSE4.2 emulator in particular. There is no way to run El Cap or another supported macOS version natively without booting OC or without adding the kernel extension manually.

Since the heat transport is really limited in these older iMacs my recommendation is:
Use a Venus family card. Both Saturn cards will draw up to 75W at full load.

Credits: @dfranetic and @internetzel for helping and testing.

 

[MrZupp]

I have a problem with a WX4170 4GB, tried the GOP and ALT_GOP variant but no luck.

My problem is that in Unigine Valley the benchmark starts ok, getting around 30-50 fps and after a few seconds everything freezes, I can't move my cursor I can't do anything, but after a while everything resumes for about 3-4 seconds and after it freezes again and then crashes and the system unfreezes.

Also, I can't play anything on windows as everything has around 1-2 fps and after a few seconds the whole system freezes and needs to be rebooted to work again, otherwise I can watch 4k60 videos no problem, temps are under 40-45°C and I haven't encountered any other issue while using Windows/Ventura normally. ( No load on the GPU )

Using an iMac12,2.

It should be mentioned that I'm using the BIOS chip from the old HD6970M, maybe that's the issue, but I've trimmed the FFFFF parts of the vbios to fit the chip.

I will attach the current vBIOS that I'm using ( ALT variant ) alongside the other vBIOS and the crash log from unigine valley.

 

[internetzel]

I have a problem with a WX4170 4GB, tried the GOP and ALT_GOP variant but no luck.

My problem is that in Unigine Valley the benchmark starts ok, getting around 30-50 fps and after a few seconds everything freezes, I can't move my cursor I can't do anything, but after a while everything resumes for about 3-4 seconds and after it freezes again and then crashes and the system unfreezes.

Also, I can't play anything on windows as everything has around 1-2 fps and after a few seconds the whole system freezes and needs to be rebooted to work again, otherwise I can watch 4k60 videos no problem, temps are under 40-45°C and I haven't encountered any other issue while using Windows/Ventura normally. ( No load on the GPU )

Using an iMac12,2.

It should be mentioned that I'm using the BIOS chip from the old HD6970M, maybe that's the issue, but I've trimmed the FFFFF parts of the vbios to fit the chip.

I will attach the current vBIOS that I'm using ( ALT variant ) alongside the other vBIOS and the crash log from unigine valley.

Did you already try the WX4150 VBIOSes? Those differ from the W4170 VBIOSes only in clock speeds, while the whole number of shaders will still be available.
Only some WX4170s do support the higher clocks...

 

[MrZupp]

Did you already try the WX4150 VBIOSes? Those differ from the W4170 VBIOSes only in clock speeds, while the whole number of shaders will still be available.
Only some WX4170s do support the higher clocks...

I will try them on sunday and write my experience here, thanks a lot for the suggestion!

 

[beblack568]

Hello there. I bought a K4100m from a DELL PRECISION and it was working on that machine. How can I flash? I tried using GRML but after installing on iMac screen does not turn on. Also, k4100m does not have a bios chip to use a programmer.

 

[Nguyen Duc Hieu]

Hello there. I bought a K4100m from a DELL PRECISION and it was working on that machine. How can I flash? I tried using GRML but after installing on iMac screen does not turn on. Also, k4100m does not have a bios chip to use a programmer.

1. Show 2 photos of high resolution taking both side of your K4100m so we can verify that your card doesn't have a BIOS chip.
2. If it doesn't have a BIOS chip, it's actually easier: Buy a vBIOS chip, use a programer to flash vBIOS to that chip, then solder it to your card.
3. If it does, you already know what to do.

 

[beblack568]

1. Show 2 photos of high resolution taking both side of your K4100m so we can verify that your card doesn't have a BIOS chip.
2. If it doesn't have a BIOS chip, it's actually easier: Buy a vBIOS chip, use a programer to flash vBIOS to that chip, then solder it to your card.
3. If it does, you already know what to do.

As far as I know k4100 can't be flashed using a clip and it needs to be flashed with software

 

[mrlost]

Hello everyone, I have a problem with the imac of one of my daughters, the i7 2600s processor is being limited to 59%, if I reset the sms it works again, but when I turn off the imac and turn it on again it happens again. I suspect a connector that is not in good condition, do you think it could be that? I leave a photograph pointing out the connector.

 

[Methanoid]

Hello everyone, I have a problem with the imac of one of my daughters, the i7 2600s processor is being limited to 59%, if I reset the sms it works again, but when I turn off the imac and turn it on again it happens again. I suspect a connector that is not in good condition, do you think it could be that? I leave a photograph pointing out the connector.

Maybe open a thread about this rather than post in an existing GPU thread

 

[Nguyen Duc Hieu]

As far as I know k4100 can't be flashed using a clip and it needs to be flashed with software

1. It can't be flashed with a clip. But it can be flashed when the vBIOS chip has been detached from the board.
2. Your card does have a vBIOS chip.
Check post 1 or search the thread for GRML flashing guideline. You need another computer to remote control your iMac and flash it.

 

[fredflinston]

Hi Everyone!

3rd time to try in 2 years GPU swap, this time seems actually got the card I ordered (last 2 times was not correct and had to return..)

So just installed WX4150M Dell (green), flashed with https://github.com/Ausdauersportler/GRML-FLASH via SSH, initially did not have any video on int or ext until saw https://forums.macrumors.com/thread....1596614/page-362?post=28818975#post-28818975 (hardware issues), point 22, I had used the mDP port furthest from USB, once using closest, now have video int and ext displays,... am on High Sierra, System Profiler sees Polaris 4Gb video card, sleep works, Valley gives expected results (1800, 49fps), temps are within 3º with normal use, within 7º running Valley (64º gpu, 57º heatsink) (Valley shows 256Mb but as SP is correct I think this is an issue with Valley only).. BUT video does not appear until desktop appears, I almost do not see the Apple and bar, and cannot see the boot picker... (have tried shining bright light on display without glass, have seen in the past what a lack of backlight but working display looks like)

have tried adding agdpmod=vit9696 bootflag to get it working (https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/post-30232918, also tried the Nvidia patcher suggested, but w/o anything marked the install button is greyed out), but am not entirely sure that OCLP is actually being booted by the system (I understand that this card, once VBIOS flashed, does not need OCLP entirely?), as although it does seem to install correctly (and there are files present on the EFI as expected & normal), when I tried following the OCLP Troubleshooting, Booting with non-flashed GPU to try and make sure OCLP is being used, as I cannot access Recovery to disable SIP either (cmd+r just shows black screen and eventually fans slowly ramp up to about 1/2 speed after 30mins), I tried re-installing OCLP with SIP disabled (all SIP settings marked), but still the bless command gave a 0xe00002bc Could not set boot device, so I assume that OCLP is not being read..? As if it was, it should have disabled SIP and I should be able to execute the bless command??

Am trying to upgrade to BigSur (for the moment, maybe Monterey later on once I have a fully reliable BigSur install I can go back to if Monterey gives problems with wifi/bluetooth), so have prepared USB installer with same OCLP configs installed there, but as cannot see boot picker, I have tried various different key presses after ALT (arrow left 0, 1, 2, or 3 times, enter, arrow left again 0,1,2 times, enter again), including NVRAM resets on some tries, and only either come back to my HS install (and then I check with the bless command to see if SIP has been disabled, no), or black screen and do not see the BigSur installer... also have checked from another Mac that this iMac appears in Network and can ScreenShare OK, so when is black screen does not come up in Network/ cannot access

I have spent a couple of days again revising first post, various other posts, OCLP docs, and for sure I have missed something obvious that will resolve this issue as it seems to be a popular card that works very well... please indicate what I may have missed, as without the boot picker I do not know how to proceed with the BigSur Install! (I will be doing a clean install, but do not want to wipe SSD until an get to the installer... have tried to execute installer directly from HS from the USB, but won't let me choose the SSD (the update cannot be installed on this computer)).. would using dosdude Catalina Patcher to install Catalina let me later be able to use BigSur installer with OCLP..? I have seen my issue seems to be HS related, but that it is not recommended to upgrade dosdude Catalina patched OS to BigSur, so am a bit confused here... (although in theory as it would be a clean install, would not be upgrading existing, but do not want to wipe SSD with working OS and later find that also cannot reinstall HS!)


Thanks for all of the great work of you all, sorry if I have missed something obvious, completely understand that it is a drag to repeat the same over and over, but I have missed (I am sure) that golden nugget that will allow me to complete a full install, so I thank you for your indication! 🙏

Cheers!
Andy

 

[maccoops]

Hello everyone, I have a problem with the imac of one of my daughters, the i7 2600s processor is being limited to 59%, if I reset the sms it works again, but when I turn off the imac and turn it on again it happens again. I suspect a connector that is not in good condition, do you think it could be that? I leave a photograph pointing out the connector.

This has been my experience, twice in fact. The issue was bad connectors in both cases. It may be worthwhile to reseat some or all of the connectors and try again.

 

[maccoops]

Hi Everyone!

3rd time to try in 2 years GPU swap, this time seems actually got the card I ordered (last 2 times was not correct and had to return..)

So just installed WX4150M Dell (green), flashed with https://github.com/Ausdauersportler/GRML-FLASH via SSH, initially did not have any video on int or ext until saw https://forums.macrumors.com/thread....1596614/page-362?post=28818975#post-28818975 (hardware issues), point 22, I had used the mDP port furthest from USB, once using closest, now have video int and ext displays,... am on High Sierra, System Profiler sees Polaris 4Gb video card, sleep works, Valley gives expected results (1800, 49fps), temps are within 3º with normal use, within 7º running Valley (64º gpu, 57º heatsink) (Valley shows 256Mb but as SP is correct I think this is an issue with Valley only).. BUT video does not appear until desktop appears, I almost do not see the Apple and bar, and cannot see the boot picker... (have tried shining bright light on display without glass, have seen in the past what a lack of backlight but working display looks like)

have tried adding agdpmod=vit9696 bootflag to get it working (https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/post-30232918, also tried the Nvidia patcher suggested, but w/o anything marked the install button is greyed out), but am not entirely sure that OCLP is actually being booted by the system (I understand that this card, once VBIOS flashed, does not need OCLP entirely?), as although it does seem to install correctly (and there are files present on the EFI as expected & normal), when I tried following the OCLP Troubleshooting, Booting with non-flashed GPU to try and make sure OCLP is being used, as I cannot access Recovery to disable SIP either (cmd+r just shows black screen and eventually fans slowly ramp up to about 1/2 speed after 30mins), I tried re-installing OCLP with SIP disabled (all SIP settings marked), but still the bless command gave a 0xe00002bc Could not set boot device, so I assume that OCLP is not being read..? As if it was, it should have disabled SIP and I should be able to execute the bless command??

Am trying to upgrade to BigSur (for the moment, maybe Monterey later on once I have a fully reliable BigSur install I can go back to if Monterey gives problems with wifi/bluetooth), so have prepared USB installer with same OCLP configs installed there, but as cannot see boot picker, I have tried various different key presses after ALT (arrow left 0, 1, 2, or 3 times, enter, arrow left again 0,1,2 times, enter again), including NVRAM resets on some tries, and only either come back to my HS install (and then I check with the bless command to see if SIP has been disabled, no), or black screen and do not see the BigSur installer... also have checked from another Mac that this iMac appears in Network and can ScreenShare OK, so when is black screen does not come up in Network/ cannot access

I have spent a couple of days again revising first post, various other posts, OCLP docs, and for sure I have missed something obvious that will resolve this issue as it seems to be a popular card that works very well... please indicate what I may have missed, as without the boot picker I do not know how to proceed with the BigSur Install! (I will be doing a clean install, but do not want to wipe SSD until an get to the installer... have tried to execute installer directly from HS from the USB, but won't let me choose the SSD (the update cannot be installed on this computer)).. would using dosdude Catalina Patcher to install Catalina let me later be able to use BigSur installer with OCLP..? I have seen my issue seems to be HS related, but that it is not recommended to upgrade dosdude Catalina patched OS to BigSur, so am a bit confused here... (although in theory as it would be a clean install, would not be upgrading existing, but do not want to wipe SSD with working OS and later find that also cannot reinstall HS!)


Thanks for all of the great work of you all, sorry if I have missed something obvious, completely understand that it is a drag to repeat the same over and over, but I have missed (I am sure) that golden nugget that will allow me to complete a full install, so I thank you for your indication! 🙏

Cheers!
Andy

Good effort! I'm a noob, and am having my own problems, but I see a suggestion for booting from terminal which may assist you? It's found at this page in the OCLP docs, you need to click and expand the

Note for Mac Pros/Xserves/iMacs with unflashed GPUs

section in order to see the commands.

There again it may be beneficial to fix the problem with the display of the boot picker before taking such an approach.

 

[Nguyen Duc Hieu]

Hi Everyone!

3rd time to try in 2 years GPU swap, this time seems actually got the card I ordered (last 2 times was not correct and had to return..)

So just installed WX4150M Dell (green), flashed with https://github.com/Ausdauersportler/GRML-FLASH via SSH, initially did not have any video on int or ext until saw https://forums.macrumors.com/thread....1596614/page-362?post=28818975#post-28818975 (hardware issues), point 22, I had used the mDP port furthest from USB, once using closest, now have video int and ext displays,... am on High Sierra, System Profiler sees Polaris 4Gb video card, sleep works, Valley gives expected results (1800, 49fps), temps are within 3º with normal use, within 7º running Valley (64º gpu, 57º heatsink) (Valley shows 256Mb but as SP is correct I think this is an issue with Valley only).. BUT video does not appear until desktop appears, I almost do not see the Apple and bar, and cannot see the boot picker... (have tried shining bright light on display without glass, have seen in the past what a lack of backlight but working display looks like)

have tried adding agdpmod=vit9696 bootflag to get it working (https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/post-30232918, also tried the Nvidia patcher suggested, but w/o anything marked the install button is greyed out), but am not entirely sure that OCLP is actually being booted by the system (I understand that this card, once VBIOS flashed, does not need OCLP entirely?), as although it does seem to install correctly (and there are files present on the EFI as expected & normal), when I tried following the OCLP Troubleshooting, Booting with non-flashed GPU to try and make sure OCLP is being used, as I cannot access Recovery to disable SIP either (cmd+r just shows black screen and eventually fans slowly ramp up to about 1/2 speed after 30mins), I tried re-installing OCLP with SIP disabled (all SIP settings marked), but still the bless command gave a 0xe00002bc Could not set boot device, so I assume that OCLP is not being read..? As if it was, it should have disabled SIP and I should be able to execute the bless command??

Am trying to upgrade to BigSur (for the moment, maybe Monterey later on once I have a fully reliable BigSur install I can go back to if Monterey gives problems with wifi/bluetooth), so have prepared USB installer with same OCLP configs installed there, but as cannot see boot picker, I have tried various different key presses after ALT (arrow left 0, 1, 2, or 3 times, enter, arrow left again 0,1,2 times, enter again), including NVRAM resets on some tries, and only either come back to my HS install (and then I check with the bless command to see if SIP has been disabled, no), or black screen and do not see the BigSur installer... also have checked from another Mac that this iMac appears in Network and can ScreenShare OK, so when is black screen does not come up in Network/ cannot access

I have spent a couple of days again revising first post, various other posts, OCLP docs, and for sure I have missed something obvious that will resolve this issue as it seems to be a popular card that works very well... please indicate what I may have missed, as without the boot picker I do not know how to proceed with the BigSur Install! (I will be doing a clean install, but do not want to wipe SSD until an get to the installer... have tried to execute installer directly from HS from the USB, but won't let me choose the SSD (the update cannot be installed on this computer)).. would using dosdude Catalina Patcher to install Catalina let me later be able to use BigSur installer with OCLP..? I have seen my issue seems to be HS related, but that it is not recommended to upgrade dosdude Catalina patched OS to BigSur, so am a bit confused here... (although in theory as it would be a clean install, would not be upgrading existing, but do not want to wipe SSD with working OS and later find that also cannot reinstall HS!)


Thanks for all of the great work of you all, sorry if I have missed something obvious, completely understand that it is a drag to repeat the same over and over, but I have missed (I am sure) that golden nugget that will allow me to complete a full install, so I thank you for your indication! 🙏

Cheers!
Andy

The good news here is you have got a working card, your iMac is working well.
All the mess-ups were caused by human errors only.
How to fix it:
1. On a working Mac computer, create a Big Sur disk. (This mean an SSD with Mac OS Big Sur installed and run well.)
2. On your iMac 2011 with WX4150 and High Siera running:
- Attach the Big Sur Disk to a USB port
- Run OCLP manually with destination disk is the Big Sur disk.

3. Now turn off the iMac 2011 and replace the High Sierra disk with the Big Sur disk you have just fix.

4. Enjoy the result of your hard work.

 

[beblack568]

1. It can't be flashed with a clip. But it can be flashed when the vBIOS chip has been detached from the board.
2. Your card does have a vBIOS chip.
Check post 1 or search the thread for GRML flashing guideline. You need another computer to remote control your iMac and flash it.

In OP says only k1000,k1100,k2000 and k2100 can be flashed using a clip because other Nvidia cards have a different chip that can only be flashed using software. However I installed a bootcamp partition and will try to flash that way

 

[fredflinston]

Good effort! I'm a noob, and am having my own problems, but I see a suggestion for booting from terminal which may assist you? It's found at this page in the OCLP docs, you need to click and expand the

Note for Mac Pros/Xserves/iMacs with unflashed GPUs

section in order to see the commands.

There again it may be beneficial to fix the problem with the display of the boot picker before taking such an approach.

Thanks for the tip! I knew I had seen the complete process somewhere but only could find the final bless command on the troubleshooting page...!

So this has led me to realize I don't have a Recovery Partition installed (this iMac has been updated/upgraded IDK how many times, not sure when I lost it).. and also that my SSD is HFS+, when it should be APFS (installer should have automagically always convert.. again, IDK when/why!), so when I use the first NVRAM command, it just comes back to my HS OS 🤦
currently looking how to reinstall Recovery, seen a Combo update may do it, otherwise I have a USB HS installer and will install on top, shouldn't affect the working system 🤞

the problem so far was that trying to use cmd+r didn't work either (but just left me with black screen, did not come back to HS OS), so hopefully either method for reaching Recovery will work once I have Recovery, and can see if my machine will actually SHOW the Recovery utility and can disable SIP to try the bless command, etc.. which hopefully will make the boot picker visible! 🤞

Thanks again for the tip!
Andy

 

[fredflinston]

The good news here is you have got a working card, your iMac is working well.
All the mess-ups were caused by human errors only.
How to fix it:
1. On a working Mac computer, create a Big Sur disk. (This mean an SSD with Mac OS Big Sur installed and run well.)
2. On your iMac 2011 with WX4150 and High Siera running:
- Attach the Big Sur Disk to a USB port
- Run OCLP manually with destination disk is the Big Sur disk.

3. Now turn off the iMac 2011 and replace the High Sierra disk with the Big Sur disk you have just fix.

4. Enjoy the result of your hard work.

Hi Nguyen,

Sounds like a plan if I cannot get the Recovery + bless OCLP boot to work... but this will requiere another SSD, which I do not have right now (but thinking about it, the SSD I have HS install is more than 6 years old (more like 7-8 I think I have it since Capitan!)), so maybe a good time to get a new one!

Would you recommend anything special for the OCLP settings..? At the moment I had installed with SIP removed in an attempt to get the bless command to work, SMBios moderate, Model iMac12,2, but spoof to iMacPro1,1 (can't remember where/why I saw this last change to make, too many posts searched these last few days!)*

Thanks!
Andy


Edit: * that said, am really still not sure that the iMac is even using the OCLP boot files, I'm not sure if this card, as is now flashed OK, needs OCLP to be able to (minimally) boot..? Maybe the effect I see is because is not using the OCLP patching/mods during the boot..?

 

[fredflinston]

A small (but sufficient) step forward @maccoops! in the end had to use the USB HS installer, erased SSD and made sure was AFPS this time, installed, got up and running, and then went to do the recommended steps you commented above (after checking that issue was still present, and then installing OCLP as mentioned to SSD, and then checking that even thou I had configured OCLP to disable SIP, it was still active, so WAS booting w/o reading OCLP 😜).. this time I could access Recovery and bless the OCLP booter, and now I have video as soon as the booter is loaded, but not before... so if I press ALT, even if I do not press any arrows, just enter, it no longer enters any OS just stays on black screen 🤔

But this is sufficient for me to now be sure that the BigSur installer is visible, and am now installing BigSur, whereafter will again install OCLP and revise if root patches are now necessary... hopefully then will get visibility on power on, and can see what happens with ALT, but will have achieved my goal of finally having an OS that I can use various programs that had been left w/o support on HS 👏

Maybe will go ahead with Nyugen plan of making a BigSur SSD on another machine, as I will be putting in a new SSD anyway now for sure, just to make sure the old SSD does not fail in the near future.. also will be interesting to see if there is any difference in how the iMac behaves 👍

Thanks for the quick replies and the tip that helped out of the dead end!

Cheers!
Andy

 

[bkiben]

Hi!

I bought gtx 880M gpu. I replaced in my iMac 27 2011. Bios updated, in external display allwas good, but iMac display not working, black screen. The motherboard light 3 green led. What could be the problem?

 

[fredflinston]

Hi!

I bought gtx 880M gpu. I replaced in my iMac 27 2011. Bios updated, in external display allwas good, but iMac display not working, black screen. The motherboard light 3 green led. What could be the problem?

IDK, I do not have a Nvidia card, but quick look:

https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/#:~:text=Known%20issues%20or-,problems,-%3A

point 7
..?

 

[Nguyen Duc Hieu]

A small (but sufficient) step forward @maccoops! in the end had to use the USB HS installer, erased SSD and made sure was AFPS this time, installed, got up and running, and then went to do the recommended steps you commented above (after checking that issue was still present, and then installing OCLP as mentioned to SSD, and then checking that even thou I had configured OCLP to disable SIP, it was still active, so WAS booting w/o reading OCLP 😜).. this time I could access Recovery and bless the OCLP booter, and now I have video as soon as the booter is loaded, but not before... so if I press ALT, even if I do not press any arrows, just enter, it no longer enters any OS just stays on black screen 🤔

But this is sufficient for me to now be sure that the BigSur installer is visible, and am now installing BigSur, whereafter will again install OCLP and revise if root patches are now necessary... hopefully then will get visibility on power on, and can see what happens with ALT, but will have achieved my goal of finally having an OS that I can use various programs that had been left w/o support on HS 👏

Maybe will go ahead with Nyugen plan of making a BigSur SSD on another machine, as I will be putting in a new SSD anyway now for sure, just to make sure the old SSD does not fail in the near future.. also will be interesting to see if there is any difference in how the iMac behaves 👍

Thanks for the quick replies and the tip that helped out of the dead end!

Cheers!
Andy

Another option you can try. But it's really inconvenient to do things with only 1 SSD and 1 USB flash drive.
1. Re-install High Sierra to the SSD. (with the original graphic card if you can't do it with the new WX4150)
2. Install OCLP to the SSD.
3. Create a Big Sur USB installer using OCLP.
4. Use Opencore Configurator or similar Apps to modify the config.plist, extend the Opencore menu display time to 60s or more.
5. Now reboot the iMac. DO NOT PRESS OPTION on the reboot. Wait until the OC menu display. You can press SPACE BAR to access Recovery, or PRAM reset.
6. You can select to boot from the Big Sur USB installer now.
7. After finish installing Big Sur and get it run normally, you can modify the config.plist again to reduce the OC menu display time.
But remember: With Opencore and WX4150, OPTION key will not display pre-boot configuration menu (Mac original boot screen) any more.

 

[s3eker]

Maybe you damaged some components on your logic board while performing the upgrade? it is know to happen.

Yes maybe. I change to original vga card and it’s still black screen on internal.