When you do get it to boot, go into the BIOS and look at the hardware monitor. It should say what kind of voltage levels the PS is putting out, if they are erratic and/or way off spec, then it probably is the source of the problem. If the BIOS doesn't have that functionality, you can always use a multimeter and do it yourself.
I'm only looking at a $26.00 replacement anyways.
Oh really? I wouldn't skimp on a power supply, you aren't looking at one of those cheap, high wattage, off brand ones are you?