I've had and ongoing problem where my laptop screen will flick off but the computer will stay running, my fan also stays running. It occurs at random times. I could be using my laptop for hours and the problem won't occur, but It can also happen when I'm only using my laptop for 30-40mins?? I've uninstalled/reinstalled all my drivers, reinstalled my os/windows 7 but the problem is still occurring. anyone have any fix or suggestions on how I could go about fixing this problem?