I recently got an R290 and I'm having a problem. At seemingly random points the computer just instantly shuts down. it doesnt matter what i'm doing it just shuts down after anywhere from 5 minutes to 10 hours. If i put my old graphics card in i have no problems so i presumed it was a faulty card but when i had my friend test it he had no problems what so ever. Any idea what the problem could be? I'd really appreciate the help because I've tried everything i could think off.