Whenever I start my iMac 27″ mid 2011 with Radeon 6970m, it is stuck on a grey screen. I’ve tried every possible start up option and even created an external, usb-harddrive disk with OS X (just to make sure it isn’t an issue with the hard drive) – but nothing happens. I just starts, goes into loading the files and stuff and the bar appears and then the screen suddenly turns grey.
I’ve done some research and find out that it could be the graphics card. Is there a possibility to find out which part of my iMac causes the issue (AHT isn’t working either).
Did someone have a similar issue and managed to get it fixed?