I have a nvidia geforce GTX 650 OC that i got about a month ago, and it worked completely fine up until now. I was playing Black Ops 2 and then the screen cut out and went black. I didnt know what to do so I crashed my computer and started it up again. Except when i started all I got was a black screen and nothing else, no matter how many times Ive tried I cant get it to work. When I use my onboard graphics everything works fine. Can anyone tell me what happend to it? also i have an Enermax NAXN 450w PSU.