PSU or Motherboard died out???

[mightytink]

My tower was bumped by an exploratory cat, and suddenly my screen went all pixelly - much like the old school Nintendo screen would be if the cartridge wasnt put in appropriately.

I checked all the video connections, and gave the PSU a little wack to see if anything would go "back". The CPU just shut down and off - and there was no power showing on my motherboard - and the CPU wont boot. Note: the bushings in the PSU were going bad - they would squeal quite a bit until the unit warmed up enough.

I replaced the 400W PSU with an old 200W PSU I had lying around, and nothing happened. I tried with a different 200W PSU, only connecting the motherboard and harddrive - and as soon as I stuck the AC cord to the PSU, the fans on the motherboard/tower would turn on, but the CPU wouldnt boot - and the HDD didnt sound/feel like it was turning, and I didnt hit the motherboard on button, either.

Is the PSU bad, and the 200W PSU's didnt work because they couldn't supply the load to boot?

Historical note - the morning after the CPU shut down, it booted 1 time with the original PSU to the BIOS screen, but since I didnt have a keyboard attached, it wouldnt go to windows. I then shut down, and connected the keyboard, but it wont boot anymore. Is this a motherboard going bad issue, HDD, or PSU? Thanks so much.

 

[g-paw]

The first thing I'd do is try a more powerful PSU, at least 350w but preferably 400 or 450. Some retailers like Circuitcity will let you return a PSU within a certain period of time with no restrocking fee. If that doesn't fix it, I'd take it apart including removing the mobo and test it as I added parts. Could also test the PSU in another machine