so i have a Cooler Master eXtreme Power Plus 500w and a radeon hd 7850, and everytime i put the gpu in the computer wont power on. i am currently using my friends gpu (8600 gts i believe) and it powers on with the same 6pin cable. idk if my psu is underpowered because it previously worked without problems and the computer would do this a couple time but im not sure how i fixed it and this time im just lost.