Good point about the fan plug...
It's kinda unclear...did you, (the original poster), have ANY heatsink attatched to the CPU when you powered-up?
EDIT: I just built a socket A system,m (last week), that would not post because I had the USB port improperly plugged in. Try putting tose jumpers for the audio back where they were. Sometimes motherboards, (at least in my expeirince), can be very tempormental over little crap like that.....and it WILL piss you off....trust me....