So I've had this problem for a while. From time to time, my monitor goes pitch black. I can hear stuff going on in the background, but im not able to get a signal from my graphics card. Only way i can fix that is to get my PC into sleep mode using my keyboard, and when i get it back up, scren is fine. Other than that someties it just freezes; screen is black and you can hear sound stuttering. Nothing i can do then but force restart. So i thought the problem is graphics card. But i got a new one which worked fine for about a month when problems appeared again. Both cards are low end so problems could be with the cards (first card fos Nvidia and the other one is ATI). But i was just wondering is it possible that something else is causing the problems ? I'm running a bunch of tests atm. Any clue ??