Black Screen in Boot Camp (Early 2009 iMac, Windows 10)

[yippy]

I am having big issues getting the screen/display drivers to work on my iMac in BootCamp. My iMac used to work just fine in Windows 10 that I had upgraded from Windows 7. However, I just replaced the drive with an SSD so I reinstalled Windows 10 and can't get the display to work properly.

What happened
After initial install, before installing BootCamp drivers, everything worked just fine. I then installed Boot Camp 5 drivers using an elevated command prompt trick and tried to install ATI drivers but they didn't take at first. Then Windows found and installed ATI Driver version 8.970.100.9001 as is supposed to happen according to some ATI support doc I found. After that the screen is solid black with the backlight on.

My System

• 24" iMac Early 2009
• Radeon HD 4850
• Windows 10

The Problem
iMac displays an all black screen when graphics drivers are installed. When not installed, display doesn't sleep properly and graphics performance is poor.

Things I have tried

• I tried uninstalling all of the bootcamp drivers but I still have the issue. - Still black screen
• Uninstalling the Windows provided driver and installing ATI drivers from the ATI website and from the Boot Camp packages v 3, 4, and 5. These drivers don't "take", device manager shows no driver after install and CCC says no valid card when launched.
• Plug in an external monitor - External works like normal, internal still black
• Uninstalled the Display drivers - Internal works again but external doesn't (this is fine, I don't want an external) however, this is very temporary as Windows tries to "help" and reinstalls the display drivers again after a few minutes automatically without any warning, causing the screen to go black.
• Connect with TeamViewer - Works just fine in all of the above situations, I have been using it to do all of my driver work. So glad I got it installed first!

My Musings
It seems to me that when I install the graphics card drivers, Windows/the card no longer properly recognizes the internal display and thinks it is connected to an external display or something. One thing I noticed is that the monitor listed in Device Manager is called "Generic Non-PNP Monitor", isn't Boot Camp Drivers supposed to make that non-generic?

HELP!

 

[chscag]

My System

• 24" iMac Early 2009
• Radeon HD 4850
• Windows 10

The Problem
iMac displays an all black screen when graphics drivers are installed. When not installed, display doesn't sleep properly and graphics performance is poor.

HELP!

If my memory serves me correctly, the Radeon HD 4850 in your 2009 iMac requires that the ATI mobile drivers be installed or you'll wind up with a black screen. However, that was with Windows 7 but it's probably the same with Windows 10. I don't know which drivers you've been installing but unless it's the ATI mobile drivers, they won't work. Most folks don't realize that an iMac uses mobile drivers instead of the ones designed for a desktop.

 

[yippy]

If my memory serves me correctly, the Radeon HD 4850 in your 2009 iMac requires that the ATI mobile drivers be installed or you'll wind up with a black screen. However, that was with Windows 7 but it's probably the same with Windows 10. I don't know which drivers you've been installing but unless it's the ATI mobile drivers, they won't work. Most folks don't realize that an iMac uses mobile drivers instead of the ones designed for a desktop.

I was very careful to select mobile when I downloaded the drivers from AMD (although the package it gave me I think is generic to the entire HD 4xxx line). No drivers seems to do better than having AMD drivers installed. So weird.

 

[atomicamp]

Did you ever find a solution to this problem? I'm having the same issue with windows 10 on a 2009 iMac.