Hey, I'm having a problem with a PC. It's an Athlon 2400+, 512MB, 80GB HD running Windows XP Pro. I know it's not a Mac, but I use it as a server. I left it on last night, and this morning it was off. I checked the plugs, and then realized that when the computer is plugged in there is a hum, or a buzzing sound that seems to be coming from the power supply. Does anyone know what the problem might be? Thanks.