Xfx 8600gt not letting comp power up

Hello,
so i have the xfx geforce 8600gt. it worked fine for months. then one day i shut down the comp to keep kids from messing with it and when i tried to restart the computer it would not power up at all. i took out the card and put in another card i had and the computer starts and runs fine. if i try to reinstall the 8600 again, the comp still does not get power.