Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

leo015

macrumors newbie
Original poster
Dec 10, 2016
26
4
Hello everyone!

I have an iMac 10,1 (Late 2009, 21.5 Inch, Core 2 Duo E7600, ATI Radeon HD 4670) and I can't get Windows fully working on it. I've already tried a plethora of methods for install for which none of them works completely.



The main issue at hand is that after following the process of BCA, the system reboots to install Windows and my internal screen goes completely black while my external monitor works fine. Even after completing Windows installation, updating etc. I cannot for the life of me get the internal screen working.



Things I've tried to resolve the issue:

  • Reset SMC
  • Reset PRAM
  • Uninstall drivers in Safe Mode
  • Re-installed different versions of the drivers (ones that BCA downloaded, ones directly downloaded from AMD support website for Win8/10, updated ones from Apple supposedly fixing the black screen issue).
  • Booted from CD and using CMD deleted atikmdag.sys
  • Erased/Re-installed Windows multiple times

The only way I have managed to get the internal screen working is by installing in UEFI mode. However this uses the Basic Display Adapter. When I try to update using my GPU's drivers, the external monitor works but it corrupts my internal screen. Here's a picture [www dot ibb.co/HFn5G0R].



Any help would be appreciated
 
Are any driver issues reported in the Device Manager?

Have you tried a memory test, such as MemTest? (RAM issues can often contribute to video struggles)
 
Hi, no issues reported in DM. Showing normally as the GPU without any exclamation mark. I haven't tried a MemTest but I don't think there's an issue? I dual boot OCLP Monterey and it runs fine (internal + external screens). Only with the odd freeze due to gfx acceleration not natively supported.
 
Are any driver issues reported in the Device Manager?

Have you tried a memory test, such as MemTest? (RAM issues can often contribute to video struggles)
To get back to you, MemTest is clean
 
According this page, your iMac isn't "recommended" for UEFI Windows, most likely because of the GPU. I think it is a YMMV sort of thing...
The thing is that the internal screen ONLY works with a UEFI installation. Otherwise as soon as I boot either into a legacy setup or legacy installed disk my internal screen goes completely black, no backlight whatsoever. It's like it's disabled, not even recognized in settings. Windows only detects my external monitor.

Last night I tried the official/supported method by Apple for my system. Reverted back to OSX Lion and installed using Bootcamp and a Windows 7 Legacy x86 installation disc.

Basically same thing. As soon as I booted into the disc, black screen. Setup finished, installed Bootcamp drivers, black screen. Although the difference this time is that the ATI Catalyst software detects both monitors, the internal one is still black, disabled or whatever.

Perhaps GPU or firmware flashing may help? What about using another boot manager like rEFInd or something like that? I'm just throwing ideas at this point.
 
Last edited:
Another update, I discovered today that this issue does not only affect Windows, but Linux as well. Tried to boot off a Zorin OS dvd I have in Legacy mode and behold, iMac screen turned off - external monitor turned on. So it sounds like it's something to do with the Mac's firmware (bios) or whatever?
 
Last edited:
Had a 2009 iMac but with a Geforce 9400 instead. Windows 10 would install but not recognize the proper Graphics drivers. Installing the BootCamp drivers or official NVidia drivers would prevent if from booting.

As far as I remember I installed it in MBR mode, not UEFI? Anyway here is a post that might help point you in the right direction, even if this is another graphics card.
 
  • Like
Reactions: Dayo and leo015
Had a 2009 iMac but with a Geforce 9400 instead. Windows 10 would install but not recognize the proper Graphics drivers. Installing the BootCamp drivers or official NVidia drivers would prevent if from booting.

As far as I remember I installed it in MBR mode, not UEFI? Anyway here is a post that might help point you in the right direction, even if this is another graphics card.
Thanks for your reply. I tried both installations - UEFI and MBR. In MBR mode, my iMac's screen is completely black, Did yours work/get detected? If I then connect an external monitor, only the external monitor is recognzied in Display Settings.
 
I don't believe it's defective as it works as it should under Mac OS only. Internal + External monitors working fine. Even if I boot from a UEFI device (USB/DISC/Installation) the internal screen works fine. It's only when I boot from a Legacy (BIOS) device (DISC/Installation) that the internal monitor stops working. So I'm assuming it's something to do with the EFI BIOS emulation.
 
You could look for a firmware update in your case but I doubt it's helping.
If you're happy tinkering I think the dedicated graphics card is in MXM format and can be switched to another model.

Here can you find a comprehensive thread regarding that upgrade
 
Thanks for the link, although I believe before I start tinkering with anything hardware wise I need to try to change the register in the EFI shell. Do you happen to have any sort of guide?
 
Thanks for the link, although I believe before I start tinkering with anything hardware wise I need to try to change the register in the EFI shell. Do you happen to have any sort of guide?

I haven't looked into that much but this may point you forward

 
  • Like
Reactions: leo015
Hello everyone!

I have an iMac 10,1 (Late 2009, 21.5 Inch, Core 2 Duo E7600, ATI Radeon HD 4670) and I can't get Windows fully working on it. I've already tried a plethora of methods for install for which none of them works completely.
Hi, I have a few things to say that perhaps... may help, I don't know for sure.

Let me explain first a reference, then I will jump to what I think are key points. I have a 27" late 2009 working perfectly running Windows 10 (also tried Windows 8.1 and Windows 11). The thing is I had some issues installing Windows, during my research I read that divers can be a pain... and some things work easier in MBR but some won't work at all (like... sound, I think), but on the other side, via EFI, some things would be easier but no full display resolution, something like that; please don't attack the lack of specifics here, I'm just stating there are differences, pros and cons between MBR and EFI, and other things according to testimonials.

Being that said, in the process of installing Windows my (original) graphics card died, yes I experienced black screen, artifacts, etc. So, I don't know if those issues (just like yours) happened due to having a dying GPU. Then I got a non officially supported GPU, this means it doesn't work under MacOSX unless you do a log of gymnastics, but... I don't care because I wanted to run Windows on this machine. Still, I had some issues, you could say similar to yours... did you open your mac?, if so, check the VSYNC cable, this is a ribbon on the left. At some point I forgot to plug it and continued trying to install dealing with black screens, and later no screen at all... until I noticed and plugged the ribbon. Later had the same issues but it was due to not plugging the ribbon correctly, I read what this does, don't remember the specifics, but yes, you can get screen or just black screen if not connected.

I tried downloading the full drivers using the Bootcamp assistant, these drivers worked perfectly except for the control panel (Bootcamp control panel) this eventually breaks your Windows, I'm telling you this just so you know, there is a method to get around this posted in this forum.

To be honest, I got tired of installing, and due to replacing the GPU kills the boot from USB capabilities, I ended just installing Windows 10 on an SSD internally on a different computer using full MBR mode, and then moving this SSD to my iMac, it worked perfectly, and then continued to install the software. My Mac works great running Windows (8.1, 10 and 11), and Linux, but using a different GPU. Despite having diff hardware, as you can see there are some details that may be affecting you.

Back to the ribbon: before connecting it, check if the contacts are fine. Good luck, and I suggest try Linux first (at least for testing), as it uses generic drivers (Noveau).
 
  • Like
Reactions: Nguyen Duc Hieu
Hi, I have a few things to say that perhaps... may help, I don't know for sure.

Let me explain first a reference, then I will jump to what I think are key points. I have a 27" late 2009 working perfectly running Windows 10 (also tried Windows 8.1 and Windows 11). The thing is I had some issues installing Windows, during my research I read that divers can be a pain... and some things work easier in MBR but some won't work at all (like... sound, I think), but on the other side, via EFI, some things would be easier but no full display resolution, something like that; please don't attack the lack of specifics here, I'm just stating there are differences, pros and cons between MBR and EFI, and other things according to testimonials.

Being that said, in the process of installing Windows my (original) graphics card died, yes I experienced black screen, artifacts, etc. So, I don't know if those issues (just like yours) happened due to having a dying GPU. Then I got a non officially supported GPU, this means it doesn't work under MacOSX unless you do a log of gymnastics, but... I don't care because I wanted to run Windows on this machine. Still, I had some issues, you could say similar to yours... did you open your mac?, if so, check the VSYNC cable, this is a ribbon on the left. At some point I forgot to plug it and continued trying to install dealing with black screens, and later no screen at all... until I noticed and plugged the ribbon. Later had the same issues but it was due to not plugging the ribbon correctly, I read what this does, don't remember the specifics, but yes, you can get screen or just black screen if not connected.

I tried downloading the full drivers using the Bootcamp assistant, these drivers worked perfectly except for the control panel (Bootcamp control panel) this eventually breaks your Windows, I'm telling you this just so you know, there is a method to get around this posted in this forum.

To be honest, I got tired of installing, and due to replacing the GPU kills the boot from USB capabilities, I ended just installing Windows 10 on an SSD internally on a different computer using full MBR mode, and then moving this SSD to my iMac, it worked perfectly, and then continued to install the software. My Mac works great running Windows (8.1, 10 and 11), and Linux, but using a different GPU. Despite having diff hardware, as you can see there are some details that may be affecting you.

Back to the ribbon: before connecting it, check if the contacts are fine. Good luck, and I suggest try Linux first (at least for testing), as it uses generic drivers (Noveau).

Maybe you didn't read through all OP posts. His iMac runs Monterrey fine, just without graphic acceleration (natural issue of AMD HD4670)


His Windows installation went well until Windows tried to load graphic driver and proceeded to Windows desktop. At this point the connection (video signal transmission) between the MXM card and the internal display snapped, while it still sending signal through the miniDisplayport to the external display.

Solution: Either be consent with only Monterey (until the graphic card dies completely), or replace the graphic card.

To verify that your graphic card is dying: Boot the iMac with a native supported Mac OS version like High Sierra and run some stress test programs. But the risk is that you might completely knock down the graphic card, rendering the iMac unusable. I would just keep it at the current status and run Monterey.
 
  • Like
Reactions: leo015
Hi, I have a few things to say that perhaps... may help, I don't know for sure.

Let me explain first a reference, then I will jump to what I think are key points. I have a 27" late 2009 working perfectly running Windows 10 (also tried Windows 8.1 and Windows 11). The thing is I had some issues installing Windows, during my research I read that divers can be a pain... and some things work easier in MBR but some won't work at all (like... sound, I think), but on the other side, via EFI, some things would be easier but no full display resolution, something like that; please don't attack the lack of specifics here, I'm just stating there are differences, pros and cons between MBR and EFI, and other things according to testimonials.

Being that said, in the process of installing Windows my (original) graphics card died, yes I experienced black screen, artifacts, etc. So, I don't know if those issues (just like yours) happened due to having a dying GPU. Then I got a non officially supported GPU, this means it doesn't work under MacOSX unless you do a log of gymnastics, but... I don't care because I wanted to run Windows on this machine. Still, I had some issues, you could say similar to yours... did you open your mac?, if so, check the VSYNC cable, this is a ribbon on the left. At some point I forgot to plug it and continued trying to install dealing with black screens, and later no screen at all... until I noticed and plugged the ribbon. Later had the same issues but it was due to not plugging the ribbon correctly, I read what this does, don't remember the specifics, but yes, you can get screen or just black screen if not connected.

I tried downloading the full drivers using the Bootcamp assistant, these drivers worked perfectly except for the control panel (Bootcamp control panel) this eventually breaks your Windows, I'm telling you this just so you know, there is a method to get around this posted in this forum.

To be honest, I got tired of installing, and due to replacing the GPU kills the boot from USB capabilities, I ended just installing Windows 10 on an SSD internally on a different computer using full MBR mode, and then moving this SSD to my iMac, it worked perfectly, and then continued to install the software. My Mac works great running Windows (8.1, 10 and 11), and Linux, but using a different GPU. Despite having diff hardware, as you can see there are some details that may be affecting you.

Back to the ribbon: before connecting it, check if the contacts are fine. Good luck, and I suggest try Linux first (at least for testing), as it uses generic drivers (Noveau).

I've tried a number of things to try and pinpoint what the issue is.

1)Tried MBR installation
2)Tried UEFI installation
3)Tried Legacy drivers from Bootcamp 4
4)Tried 'updated' drivers for my GPU directly from AMD's website
5)Tried to install other OSs or boot from bootable discs, both in Legacy Mode (CSM BIOS Emulation).

As you said each has its pros and cons. However, when I tried out number 5 I discovered that this replicates the black screen issue on the built in display while the external monitor works.

Hence from the available info I believe that the problem is something to do with the Mac's BIOS emulation and not a Windows driver issue nor a hardware failure.

I'm also running High Sierra on another partition without any issues. All screens working.

The obstacle is that I'm unsure of what to change in the shell register, if anyone want's to chime in and help!
 
Maybe you didn't read through all OP posts. His iMac runs Monterrey fine, just without graphic acceleration (natural issue of AMD HD4670)


His Windows installation went well until Windows tried to load graphic driver and proceeded to Windows desktop. At this point the connection (video signal transmission) between the MXM card and the internal display snapped, while it still sending signal through the miniDisplayport to the external display.

Solution: Either be consent with only Monterey (until the graphic card dies completely), or replace the graphic card.

To verify that your graphic card is dying: Boot the iMac with a native supported Mac OS version like High Sierra and run some stress test programs. But the risk is that you might completely knock down the graphic card, rendering the iMac unusable. I would just keep it at the current status and run Monterey.

Hi, just for the record I managed to get GFX acceleration using OpenCore's patcher. There are some issues with the OS just freezing though.

As I replied above, I don't believe it's a GPU hardware issue.

Please take a look at the following links of people having the same issue even on Linux. They manage to fix it with a kernel patch.








Now the thing to figure out is how to fix this issue but for Windows. Till now I've managed to install rEFInd and Inte's EFI Shell 1.10. However I'm unsure of what to change in the register to test it out.
 
  • Like
Reactions: Nguyen Duc Hieu
If it works as intended on Mac OS HS then why would it not be good?

Regarding the video, I've tried this. All it does is delete the ATI driver.

All I do from where I am is guessing. You can take it as reference, or not.

I think with all the research you did, you have already come to the conclusion that the issue is lying on the signal type to communicate between the MXM card and the LCD panel (LVDS vs eDP). In Mac OS, OCLP team did a wonderful job on this issue, thus no issue.
In Windows, this issue has persisted since 2015 with no consistent solution. Most of them you have tried with no positive result.

I suppose you have already tried to install Windows 7, then upgrade to Windows 10. (retaining the old Windows 7 bootcamp driver)
I suppose you have tried removing the auto-installed AMD driver, then re-install the obsolete Windows 7 Catalyst driver.
What else can you try? Editing a Windows driver file is quite complicated....
 
All I do from where I am is guessing. You can take it as reference, or not.

I think with all the research you did, you have already come to the conclusion that the issue is lying on the signal type to communicate between the MXM card and the LCD panel (LVDS vs eDP). In Mac OS, OCLP team did a wonderful job on this issue, thus no issue.
In Windows, this issue has persisted since 2015 with no consistent solution. Most of them you have tried with no positive result.

I suppose you have already tried to install Windows 7, then upgrade to Windows 10. (retaining the old Windows 7 bootcamp driver)
I suppose you have tried removing the auto-installed AMD driver, then re-install the obsolete Windows 7 Catalyst driver.
What else can you try? Editing a Windows driver file is quite complicated....
I appreciate your input don't get me wrong, I'm just thinking out loud.

I think with all the research you did, you have already come to the conclusion that the issue is lying on the signal type to communicate between the MXM card and the LCD panel (LVDS vs eDP)

I believe so that is the problem yes and the answer is somewhere within the EFI parameters. Because this only happens with Legacy (CSM BIOS) boot.

I suppose you have already tried to install Windows 7, then upgrade to Windows 10. (retaining the old Windows 7 bootcamp driver)
I suppose you have tried removing the auto-installed AMD driver, then re-install the obsolete Windows 7 Catalyst driver.

You are correct! That is why I'm saying that it must be the EFI. There is nothing else left at this point.
 
  • Like
Reactions: Nguyen Duc Hieu
It should be possible using the legacy version of Windows.
I got Windows 11 installed on my early 2009 24" using the plop boot manager and a legacy Windows usb installer:

Schermafbeelding 2024-04-05 113714.png
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.