I took the computer that I built last August apart because I thought I the computer would shut off randomly. I'm pretty sure it's not the power supplies fault. Anyway, When I only have the video card, memory, cpu, motherboard, keyboard, mouse, monitor, and power-switch from the case setup, I can't get a video signal. The system will start, the fans on the cpu and video card spin but no video signal. What's the problem? My video card used to work before I took my system apart!