Is this a PSU problem?

Hello:

Last week my PC started shutting off every so often.. then to the point where it would shut off right after it was booted- then to the point where it shut off right after post screen. The only way to get it to power on a little is by turning toggle switch on PSU off, and then on- then try to power system up, where the same problem occurs. At first I thought that perhaps there had been a motherboard failiure related to bad capacitors, but I ruled that out last night after swapping in a brand new mobo and the same problem occurs. (In a way that is a relief, as the HDD's are SATA RAID 0 and I don't have backup of all the data.)

Could this be a power supply issue? With the motherboard ruled out and no beep codes to suggest a memory or processor issue (processor fan is working nicely), I can't think of anything else but the power supply that could be causing the problem.

Right now, it would seem I should be able to swap in a new PSU, put the original ABIT IC7-MAX3 back in and I should be able to boot right back up with no problems... BUT.. I think I might sacrifice drive speed and promote backups by going to RAID 1 at some point.. as this was a headache.

Thanks!

D'OH! Good suggestion.. actually have another PC in the house with which I could swap PSU's. I'll try that tonite.

was definitely the power supply- replaced it at system booted up as good as new.