Since many of you have issues getting your AMD Radeon HD 6000 series card to work in Mountain Lion (when it worked great in Lion), I decided to make this guide.
Part 1: Setting up the ###### Drive
1. Insert your ###### Flash Drive into a working Mac. Maybe your MacBook Pro, working Lion installation, etc.
2. Run this command in terminal to unhide files "defaults write com.apple.finder AppleShowAllFiles 1" (copy and paste that into terminal and hit enter)
3. Force Finder to quit. You can do this in activity monitor. It will automatically restart.
4. Open Finder and navigate to your ###### Drive
5. Navigate to System/Library/Extensions
6. MAKE A BACKUP OF the kext "ATI6000Controller.kext" and then DELETE it.
Part 2: Booting from your ###### Drive
1. Boot from your ###### drive like you usually would. Use the command "GraphicsEnabler=No" in order to boot into Mountain Lion Installer
2. Install Mountain Lion as you usually would
3. After installation, bootup Mountain Lion by booting into your flash drive and then booting into ML, using the command "GraphicsEnabler=No"
4. Copy the ATI6000Controller.kext kext to your new desktop
5. Run ###### (Download: http://www.tonymacx8...do=cat&id=3)
Now your graphics should work. I have two monitors (Apple Cinema Display and another 25" 1080p monitor) running with full graphics acceleration Very fast and no lag!
For those wondering, I fixed my machine in my sig by replacing the parts with the exact same things. Not everything blew. I now run a surge protector on my phone line and computer.
to get my HD6970 working, so I will reinstall ML... yesterday evening I had no luck recognizing my HD3000... another problem: I'm installing ML without a bootloader, so I have to boot with the bootloader taken from the USB flash drive used for the installation... yesterday I tried then to install a bootloader to boot directly from HDD and not from flash drive, I tried chimera and chameleon, but both of them gave me always a kernel panic... the only way to boot up the system was using the bootloader from the flash drive (a different version of chameleon I suppose) and booting in safe mode. any ideas? I'm thinkin on giving up with this... nothing seems to work as it should...
EDIT: tried that. the positive thing is that now I can boot WITHOUT safe mode... the bad thing is that if I try to boot directly with my hd6970 I just have a white screen without anything else... (I had this problem in Lion... never solved it)