Is this a CPU or Power Supply problem?

Archived from groups: comp.sys.ibm.pc.hardware.chips (More info?)

I have an AMD 1700+.

My old motherboard
<http://www.asus.com/prog/spec.asp?m=A7S333&langs=01> started to have
this problem where when I turned on the computer it would power off
after about 5 seconds. No beeps. No video. Just off.

So I purchased a new MB
<http://www.meanmachine.com/Motherboards/SocketA/MSI_KT6VLSR_Motherboard_Specs.htm>

But the problems still happens. I swapped memory, video card, and
removed unnecessary devices. No change.
Could the CPU or Power Supply be the problem?

Thanks!