No power up with gateway 835GM and geforce 8600gt

[Grandmaestro]

Hi everyone, i installed a geforce 8600 gt graphics card into my gateway 835GM PCIe but it will not power up at all. I am using a 500w power supply. I tried searching the internet for answers but haven't found any.

 

[Tmagic650]

Does the 500 watt power supply have a connector for the 8800 video card? Is it connected? If so, disconnect it to see if the computer will start