also although you said you got a 650watt psu doesnt always mean thats enough, check the amps on the 12v rails for what the graphics card needs, ive said this so many time and its easily missed, the wattage doesnt necessarily mean itll cope, you could have a 1000w psu and only 19amps on the rails and things will go wrong
on the side of the psu should be a white sticker
eg this is a 1000w
it might be 1000w but with only 18amps on the 12v theres not enough supply the graphics card,itll cope for a bit then itll pop
trust me ive seen it happen loads of time
but then again it might not be any of this, but worth a check
![[Image: zn7Nehu.jpg]](http://i.imgur.com/zn7Nehu.jpg)