Screen shutting down but pc is still running

[blud7027]

i recently upgraded my gpu to gtx 550 ti . after a day started playing diablo 3 then the screen shut down on me but the pc is still running. here's my spec
phenom ii 965
500 psu
biostar ta785 ge hd
8 gigs ram
two dvd drive
500 gb hd
. for some reason it only happens when i play games. but when im just surfing its perfect. need help please or im just gonna return the card. do i need a psu? heating up to much? need help please

 

[megagabobe1]

i believe its the gpu, or it could be your psu, can you tell me which brand your psu is??

 

[fantastik250]

Have you upgraded your drivers? It is also possible that it could be too much heat.