iMac 2011 Randomly Restart. Graphics Issue?
My iMac keeps restarting randomly. Often just seconds after power up and sometimes after a long time. The screen simply goes black and then I hear the boot chime. I saw several topics about this issue with mid 2011 27" iMac and I don't really know what to do.
Is this really a graphics card failure that restarts my iMac randomly? (Radeon HD 6970M) Am I stupid to go and spend $250 on another one and try?
EDIT:
I've removed my GPU card
EDIT 12-16-2017