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I have an iMac 11,1 (27" 2009) with a WX4150, I can successfully install Catalina 10.15.5 but not 10.15.6. The iMac firmware was updated with High Sierra in the past, but the patcher gives me the warning I have to update the firmware again. The system works flawlessly with 10.15.5 and boots APFS correctly.


Installing 10.15.6 completes the first files copy, then the system reboots as normal. But during the second install screen with the apple logo, the indicator touches the 40-50% then an error pops up saying the system is not compatible.


Actual Boot ROM Version: IM111.0039.B00 (is it the latest?)


I can't reinstall High Sierra to reflash the firmware as per apple rule, since the new GPU is not recognized and the old ATI 4850 is definitively dead, the OfficialAPFSFWUpdate.dmg linked into the Catalina Patcher installs, but no firmware updates occurs at reboot.

I don't have more ideas, so I'm asking for help. Thank you!
I have a clever idea but it only works if:
1. You own another High Sierra compatible Mac
2. You have either a FireWire 800 or Thunderbolt cable.
3. Your iMac is capable of entering Target Disk Mode
What you can do is put your iMac in Target Disk Mode. And use another Mac to complete the install.

Actually from what i recall GOP flashed cards cannot enter Target Disk Mode.

Actually here is a simpler idea. Create a High Sierra install to an external HDD/SSD (using another Mac) and then use either Carbon Copy Cloner to clone the disk over to the internal Partition. Disk utility might complete the clone as well, but it likes to complain alot.

Your iMac should be running firmware 215.0.0.0.0, does your current firmware support APFS booting?
 
[/QUOTE]
I have a clever idea but it only works if:
1. You own another High Sierra compatible Mac
2. You have either a FireWire 800 or Thunderbolt cable.
3. Your iMac is capable of entering Target Disk Mode
What you can do is put your iMac in Target Disk Mode. And use another Mac to complete the install.

Actually from what i recall GOP flashed cards cannot enter Target Disk Mode.

Actually here is a simpler idea. Create a High Sierra install to an external HDD/SSD (using another Mac) and then use either Carbon Copy Cloner to clone the disk over to the internal Partition. Disk utility might complete the clone as well, but it likes to complain alot.

Your iMac should be running firmware 215.0.0.0.0, does your current firmware support APFS booting?

Actual Boot ROM Version: IM111.0039.B00 and it supports APFS, I updated it in June with High Sierra and the ATI 4850 but at this point I suppose Apple did a second firmware update since Catalina patcher is asking for it again.

Yes, I have a 2012 MBPr with a GTX 650m, I did a high sierra install on a USB drive and tried to boot it on the iMac, it boots but no display, so I believe the installation gets only the drivers needed for the MBPr.

BTW I'll try to reinstall 10.15.6 removing the OpenCore at the first reboot (it will be difficult to get the right time, the startup sound seems to be disabled during install). 10.15.5 works normally without pulling the Opencore SD, I don't know why 10.15.6 gives compatibility issues.

Anyone out there with a late 2009 iMac11,1 that can verify the latest ROM version? It'll be really helpful!
 
You didn't open terminal and "sudo reboot"?

What you can do is boot back into your installer, re-run the "post install" patches, but right before reboot. There is a CHECK BOX that must be clicked that says "force rebuild caches".
Just doing this will prevent reinstall.

Yes Catalina has issues installing kexts, it stalls rebuilding Kext cache.
You should always reboot after messing with kexts/oc.
Sudo reboot, but yes with kexts. I state it at the end of all my guides.
"A Catalina issue"™

Thanks guys, I’ll try what you suggested highvoltage12v. Just need to find a way of recreating an installer (I only had one USB stick free, and it currently has the loader on it (I just went to the shop for some more)) without a spare Mac lying around (I did have two but I gave one away at the weekend).

Yeah, the instructions about restarting were indeed clear, I had simply intended to do so once my file transfer was complete, which I ended up leaving overnight. It appears that was too long!
 
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Actual Boot ROM Version: IM111.0039.B00 and it supports APFS, I updated it in June with High Sierra and the ATI 4850 but at this point I suppose Apple did a second firmware update since Catalina patcher is asking for it again.

Yes, I have a 2012 MBPr with a GTX 650m, I did a high sierra install on a USB drive and tried to boot it on the iMac, it boots but no display, so I believe the installation gets only the drivers needed for the MBPr.

BTW I'll try to reinstall 10.15.6 removing the OpenCore at the first reboot (it will be difficult to get the right time, the startup sound seems to be disabled during install). 10.15.5 works normally without pulling the Opencore SD, I don't know why 10.15.6 gives compatibility issues.

Anyone out there with a late 2009 iMac11,1 that can verify the latest ROM version? It'll be really helpful!

Okay your iMac has APFS support. all Mac OS installs have the same driver's loaded to them, the system chooses what is 'loaded' on boot. What you need to do it boot this OS copy back up on your rMBP and then install the patched AppleGraphicsControl.kext referenced on page This will fix your Black screen issue.

Also you really should use OpenCore to boot all your OS's not just Catalina. It should be set as your default boot option/SD card.
 
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Actual Boot ROM Version: IM111.0039.B00 and it supports APFS, I updated it in June with High Sierra and the ATI 4850 but at this point I suppose Apple did a second firmware update since Catalina patcher is asking for it again.

Yes, I have a 2012 MBPr with a GTX 650m, I did a high sierra install on a USB drive and tried to boot it on the iMac, it boots but no display, so I believe the installation gets only the drivers needed for the MBPr.

BTW I'll try to reinstall 10.15.6 removing the OpenCore at the first reboot (it will be difficult to get the right time, the startup sound seems to be disabled during install). 10.15.5 works normally without pulling the Opencore SD, I don't know why 10.15.6 gives compatibility issues.

Anyone out there with a late 2009 iMac11,1 that can verify the latest ROM version? It'll be really helpful!
There is a link on post #1 to a site listing the latest firmware versions...

Installing OpenCore and macOS on your upgraded iMac

With the addition of our newer GPU, Metal is natively supported allowing for installation of macOS Mojave and Catalina with full graphics acceleration. But you need to make sure in advance you have already installed the lastest Apple firmware for your iMac. This can be done by installing High Sierra and all published Apple Update first before you can use the Catalina Loader or Mojave or Catalina.
 
There is a link on post #1 to a site listing the latest firmware versions...

Installing OpenCore and macOS on your upgraded iMac

With the addition of our newer GPU, Metal is natively supported allowing for installation of macOS Mojave and Catalina with full graphics acceleration. But you need to make sure in advance you have already installed the lastest Apple firmware for your iMac. This can be done by installing High Sierra and all published Apple Update first before you can use the Catalina Loader or Mojave or Catalina.
Okay something with the thread is broken with quoting @Maxino the latest firmware they should be running is 215.0.0.0.0 @Maxino Apple Switched to a new naming scheme around the release of 10.13.6 it shouldn't start with IM111..... Those are old firmware names
 
Hi all, after some weeks I tried to do a fresh install.

I used the manual from @Ausdauersportler and everything worked fine at first.

I used the NVIDIA config plist. But after a reboot I had only a black screen. After that I tried to use the NVIDIA iMac Pro Config plist. Catalina 10.15.6 started but after entering the password the screen went black.
Everytime I reboot / restart the iMac I can enter the password but the screen is getting black after some seconds of using the iMac. Does anyone know what I can do?
 
Can you share the Dell 6770M 1GB VBIOS? I also have an Apple VBIOS with the same card. I tried only 512 MB of video memory. It was tested on the 2011 27 "model. One vbios is 1 gb, but in tests on the 2011/27 model it had a boot screen but couldn't get into the macos or windows7
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Thats not true, it works fine. I'm guessing the dell card you tried was also dead, thats why it freezed for you. But for me, it worked fine, i sold my old 21.5 iMac with a card like that. Someone on the forums even sent me a 1gb version of the Apple firmware and that worked fine too: https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/page-67#post-27080233
Can you share the Dell 6770M 1GB VBIOS? I also have an Apple VBIOS with the same card. I tried only 512 MB of video memory. It was tested on the 2011 27 "model. One vbios is 1 gb, but in tests on the 2011/27 model it had a boot screen but couldn't get into the macos or windows7
 
Hi all, after some weeks I tried to do a fresh install.

I used the manual from @Ausdauersportler and everything worked fine at first.

I used the NVIDIA config plist. But after a reboot I had only a black screen. After that I tried to use the NVIDIA iMac Pro Config plist. Catalina 10.15.6 started but after entering the password the screen went black.
Everytime I reboot / restart the iMac I can enter the password but the screen is getting black after some seconds of using the iMac. Does anyone know what I can do?
Go back to the stock Nvidia config.plist, search the first post for „black screen“. Known issue...
 
Hello! I have an old 27" iMac (Core i5 3.1GHz, mid 2011) with a dead GPU that I would like to try to revive. Just found this forum post and I must say its really amazing how much hard work you guys have put into this. Fantastic.

Now, I'm trying to read up on exactly what card to get and how to swap it out to get everything working but I'm unsure if I'm looking at the latest information. Would really appreciate if someone could help me out.
  • I'm looking to get a card preferrably for less than $200. Am I correct that the K4100 would be the best to get in that price range? Or does anyone know of a seller that has the correct version of the AMD cards?
  • If I get the K4100 it should be a Dell one right? Is this the right one: https://www.aliexpress.com/item/32881147889.html
  • I don't remember exactly what version of OSX the iMac runs, but it most definitely does not have the latest security updates. Do I need to make sure its updated before I switch cards or can I do it after? If before; do you have any suggestions on how to update the iMac, considering its not booting?
Huge thanks again for all the hard work put into this!
 
Hello! I have an old 27" iMac (Core i5 3.1GHz, mid 2011) with a dead GPU that I would like to try to revive. Just found this forum post and I must say its really amazing how much hard work you guys have put into this. Fantastic.

Now, I'm trying to read up on exactly what card to get and how to swap it out to get everything working but I'm unsure if I'm looking at the latest information. Would really appreciate if someone could help me out.
  • I'm looking to get a card preferrably for less than $200. Am I correct that the K4100 would be the best to get in that price range? Or does anyone know of a seller that has the correct version of the AMD cards?
  • If I get the K4100 it should be a Dell one right? Is this the right one: https://www.aliexpress.com/item/32881147889.html
  • I don't remember exactly what version of OSX the iMac runs, but it most definitely does not have the latest security updates. Do I need to make sure its updated before I switch cards or can I do it after? If before; do you have any suggestions on how to update the iMac, considering its not booting?
Huge thanks again for all the hard work put into this!
What is dead? GPU or backlight board?
Do you have the possibility to plug an external monitor via TB2 plug, just to begin and check?
 
What is dead? GPU or backlight board?
Do you have the possibility to plug an external monitor via TB2 plug, just to begin?

Good question. I just assumed it was the GPU because it started to behave really weird with grey lines across the screen, rebooting and eventually just a grey screen when the login is supposed to show up. Booting into safe mode works sometimes, but then it quickly freezes with strange colors and/or grey screen and reboots.
 
Hello! I have an old 27" iMac (Core i5 3.1GHz, mid 2011) with a dead GPU that I would like to try to revive. Just found this forum post and I must say its really amazing how much hard work you guys have put into this. Fantastic.

Now, I'm trying to read up on exactly what card to get and how to swap it out to get everything working but I'm unsure if I'm looking at the latest information. Would really appreciate if someone could help me out.
  • I'm looking to get a card preferrably for less than $200. Am I correct that the K4100 would be the best to get in that price range? Or does anyone know of a seller that has the correct version of the AMD cards?
  • If I get the K4100 it should be a Dell one right? Is this the right one: https://www.aliexpress.com/item/32881147889.html
  • I don't remember exactly what version of OSX the iMac runs, but it most definitely does not have the latest security updates. Do I need to make sure its updated before I switch cards or can I do it after? If before; do you have any suggestions on how to update the iMac, considering its not booting?
Huge thanks again for all the hard work put into this!
If you have a dead GPU you can use both the K3100M (N15E-Q1-A2) and the K4100M (N15E-Q3-A2). We do not advertise any sellers here nor we recommend to buy from a certain source. Depending on the continent you are living on I would try to check the Bay first for a local reseller. I found at least one from California offering a new K4100M. Buying is your own decision.
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Good question. I just assumed it was the GPU because it started to behave really weird with grey lines across the screen, rebooting and eventually just a grey screen when the login is supposed to show up. Booting into safe mode works sometimes, but then it quickly freezes with strange colors and/or grey screen and reboots.
Sounds like a dying or half dead GPU...
 
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So I had to flash back to the old Beta3 bios for my iMac 2011 with 780M.

New BIOS refused to work with anything relating to booting Windows. Bootcamp would stay stuck at boot picker frozen, rebooting into Windows stuck on grey screen forever and booting off a CD to Windows 7 does the exact same thing.

A live Linux bootable USB works as well as OSX.

Strange that it's only Windows.

Since flashing back all is OK again.
 
Hello! I have an old 27" iMac (Core i5 3.1GHz, mid 2011) with a dead GPU that I would like to try to revive. Just found this forum post and I must say its really amazing how much hard work you guys have put into this. Fantastic.

Now, I'm trying to read up on exactly what card to get and how to swap it out to get everything working but I'm unsure if I'm looking at the latest information. Would really appreciate if someone could help me out.
  • I'm looking to get a card preferrably for less than $200. Am I correct that the K4100 would be the best to get in that price range? Or does anyone know of a seller that has the correct version of the AMD cards?
  • If I get the K4100 it should be a Dell one right? Is this the right one: https://www.aliexpress.com/item/32881147889.html
  • I don't remember exactly what version of OSX the iMac runs, but it most definitely does not have the latest security updates. Do I need to make sure its updated before I switch cards or can I do it after? If before; do you have any suggestions on how to update the iMac, considering its not booting?
Huge thanks again for all the hard work put into this!
Look for a k3100m Dell/k4100m Dell card. 780M is probably out of your price range now.
 
Hello guys
need your help. I bought an imac 2011 27 inches with gpu failed and changed it with the k2100. It worked for a week then suddenly black screen. I checked the leds and the first 2 worked. at the beginning i thought it was the screen led panel board broken so i ordered a new one...nothing. then i thought it was the screen, so i bought another imac but nothing. then i thought it was the gpu, so i bought a gpu but nothing. The weird thing i noticed is that when i use the heatsink from he second imac, only the first led will turn on, when i use he old heatsink till the second will turn on.

I can hear the chime, i tried to reset the prvram but nothing. I have no idea what can be the cause. I have even tried with a new PSU, i tried with different cable and tried to plug it at different plug in my house....nothing.

the last status with the 2 leds is the fans are running super fast and loudly.
any idea?
 
Hello guys
need your help. I bought an imac 2011 27 inches with gpu failed and changed it with the k2100. It worked for a week then suddenly black screen. I checked the leds and the first 2 worked. at the beginning i thought it was the screen led panel board broken so i ordered a new one...nothing. then i thought it was the screen, so i bought another imac but nothing. then i thought it was the gpu, so i bought a gpu but nothing. The weird thing i noticed is that when i use the heatsink from he second imac, only the first led will turn on, when i use he old heatsink till the second will turn on.

I can hear the chime, i tried to reset the prvram but nothing. I have no idea what can be the cause. I have even tried with a new PSU, i tried with different cable and tried to plug it at different plug in my house....nothing.

the last status with the 2 leds is the fans are running super fast and loudly.
any idea?
See if just holding the OPTION/ALT key or the T key makes anything come up on the display. Most of the time there is no boot screen unless you request it.
 
See if just holding the OPTION/ALT key or the T key makes anything come up on the display. Most of the time there is no boot screen unless you request it.
thank you. the fact is that the used gpu are not flashed so no boot screen available. does your solution still apply here?
 
To @Ausdauersportler, @highvoltage12v, @Pascal Baillargeau, @nikey22, @NOTNICE, @herrdude and anyone else who has been a key member of the never-ending modifying, testing, and evaluation of the files, workarounds, and procedures on this thread:
YOU GUYS ARE AWESOME! 👏😃:cool:😃

Thanks to you guys (and some learning and trial and error on my own) I have brought my 27" mid-2011 i7 iMac fully back to life, including installing a 1 TB SSD, the WX7100, and upgrading it to Mojave. Starting out with High Sierra was key to help get through some of the initial stages of understanding the process. And with the most recent version of the Catalina Loader, it only made things easier when I installed the SSD and upgraded to Mojave a couple of days ago. For under $275, I now have a second functional iMac that rivals the performance of my 2017 iMac (and in some cases beats it!).

I just posted updated Valley scores (70.2, 2938) and they are essentially unchanged from what I saw and posted from my results in High Sierra about a month ago. Geekbench Metal score was 43349 (I see there is a column on the spreadsheet for this, but I couldn't find a way to enter it).

I do have one question about the GPU temperature for any others running a WX7100. In Mojave, with MacsFanControl settings for the GPU heatsink of 32 deg and 49 deg, the GPU heatsink temperature during normal daily use is around 45 degrees with the fan running around 2200 rpm. In High Sierra, with the same fan control settings and usage, the temperature was around 40 degrees. Is there any explanation for this difference in temperature? I am not too concerned about it since 45 degrees should be reasonable for my usage (no gaming). I scanned through the thread, but could not find an answer.
 
thank you. the fact is that the used gpu are not flashed so no boot screen available. does your solution still apply here?
No it wouldn't, in this case you need to try and Boot Mac OS with a Patched AppleGraphicsControl.kext on page 1. Your options are limited to taking your drive out of your iMac and installing the patched Kext with another Mac.

But you really need to flash that card. See if maybe you can get Windows 10/Linux stick to boot so you can flash the card.
 
No it wouldn't, in this case you need to try and Boot Mac OS with a Patched AppleGraphicsControl.kext on page 1. Your options are limited to taking your drive out of your iMac and installing the patched Kext with another Mac.

But you really need to flash that card. See if maybe you can get Windows 10/Linux stick to boot so you can flash the card.
the problem is that before it worked and i was going to flash the card (k2100), but now that 3rd led didn`t light up at all, and changing the heat sink will even have the 2nd let to turn on, and that is crazy. I don`t have any other gpu with me now cos all the one i have bought (k2100 and k2000) are now having the same issue...led 3 doesn`T turn on. let me try to look for the option you mentioned, but i am worried about the fact that being the 3rd led off the issue is on the gpu (broken?)
 
Is there away to hide or remove rEFInd - boot os screen? So it can boot like a normal iMac.
There was a post a couple of months ago that described how to do this. I can't remember who posted it, but you can try using the search tool at the top of the page to maybe find it.
 
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