Since last night im having trouble with my pc..I was not playing any games at all was copying some stuff over from a external harddrive to a usb flash when I got a black screen shortly after..I have a gtx 590 and 650w psu..When I got the black screen I opened my gpu case and found my gpu fan to be running at full speed but the gpu was switched off(I know its off because the evga gtx 590 has a GeForce light on its side when its up and running)nothing seemed to be happening.rebooted the pc and no black screen anymore no strange artifacts etc but there is strange coil whininh coming from my psu..and 20min after the pc boots I get the black screen with the loud gpu fan noise..any ideas whats wrong here?i tested with onboard graphic and it does not happen then,but the onboard does not put that much strain on the psu so its not a good test..