My Pc screen had been going black randomly, with no specific reason (whilst gaming may I add), and today it started doing it more frequently.. I shut down the PC, turned it back on, same issue.. I then removed the graphics card (nvidia, pretty basic card.. Nothing special, does have a fan).. Tried it again, didn't work.. I then tried my old graphics card, and the old one also first wok.. The PC starts up, all lights (keyboard), and fans are on, but no screen.. (Also no sound I think, but I'm not sure).. It's a dell Inspiron 570.. I changed the psu to a corsair cx600 (over a year ago), and I added some RAM, totalling 6gb.. I believe it's a 2,8 ghz.. Needs to be confirmed though..