I built my own computer. My motherboard is an ASUS P4S800 supports 3.0 ghz P4 and 800fsb. My cpu is an P4 2.66ghz 512 L2 cache. I got 512 mb of ram. Problem is, I start the computer, and the light on the bottom of the motherboard turns on. And thats it. No fans moving, no sounds of anything. Is it my power supply or motherboard or what? Can i fix this or do I need a new part?