iMac HD6970m GPU Upgrade Failed
I purchased a second hand "working" HD6970m off eBay and installed it in my iMac. What does work is the boot screen (initial booting as well as the boot disk select option).
Problem is when I go passed this point the boot freezes giving the warning "waiting for boot device" on a white screen. I get the same result whether I select the boot drive or USB Yosemite installer or recovery partition.
I've tried the usual SMC and PRAM resets.
I manage to boot into bootcamp (I can hear the into boot chime and the shutdown chime) but the screen stays black. I tried F8 to boot into safe mode but also no luck.
Is it possible the card is faulty? What could cause the boot error?
Any help will be greatly appreciated.
Is this a good question?