I seem to be on this streak right now where I can't even build a computer without running into problems. Heres my problem

Brand new computer

ASUS A7S333 motherboard Socket A
AMD Athlon XP 2200
300 Watt allied powersupply.
WD HD
MSI CD-RW

Ok I connect all of my switches to the motherboard plug in a power cord to the back of the PC, press the power switch, and the CPU and Case fan starts to turn but then they both stop, and of course the computer doesn't run. I've triple checked all of my wires, and connections, and re read the manual but it all seems fine. I turn the power on again, both fans start to turn for 1 second then stop.

Any ideas on what the problem might be.