I have a weird problem. Every one to several times I try to boot my PC, nothing happens when I push the power button. If I open it up and unplug and then replug in my two hard drives to the power supply, it will boot up without a problem. I'm not sure if it's a power supply problem or a drive problem or something entirely different. My home-built PC is a hodgepodge of old and new hardware.

Hard Drives: 2 WD 120gb
Processor: Dual Core 2.66 Intel
Graphics Card: All-in-Wonder 9800
Power Supply: 500watt
Optical: NEC DVD RW