I just built this computer. It is an atx case(as rock 970pro MB) and uses a old "recycled nvidia gtx620" along with a amd fx8350 and 750w power supply. When I start it all the fans(gpu and CPU fan included) spin up and all LEDs light up, the hdd light doesn't light up though, and the disk drive won't open. No image goes through the VGA or hdmi cable. When I plug the 8 pin CPU power cord it won't start up at all, except for a flash of light on the LEDs. The motherboard is brand new, the ram is brand new, the hard drive and disk drive are the only recycled parts.