What is happening!?? Computer wont post, will post, wont boot into vista, works then wont reboot, argh!

[Al Neri]

I have a PC, here are the general specs:

AMD64 3000+ socket 754 CPU @ 2.35GHz
Thermalright XP-120 heatsink/fan
Biostar K8NHA-M Grand mATX motherboard
Antec 350-watt power supply (3-year warranty)
Retail Nvidia 6200 (unlockable to 6600)
different sets of ram, see below
different hard drives, see below


. The computer worked great - out of nowhere I rebooted and it wouldn't post (no beep)
. I reseated the CPU, took all the hard drives out and replaced it with a working hard drive from another build - it finally booted, I went to install Vista, it installed and then when it booted BSOD'd rebooted and repeated over and over
. I reseated the CPU, swapped the ram with ram from a working build, reinstalled vista, same problem
. I reseated the CPU, swapped the hard drive with a working hard drive from a working build, reinstalled vista, same problem
. I reseated the CPU, tried every configuration of RAM (I had 2 512 sticks, and 2 1GB sticks (PC3200)) and reinstalled vista to no success
. I then on a whim tried and installed XP and it worked, great! whatever no vista.
. I went to reboot today and it won't post (no beep!)
. I don't remember what bios it is, and it wont post ATM so i can't tell... !

obviously > No beep - Power supply, system board problem, disconnected cpu, or disconnected speaker

- Could it be the power supply is no good? i haven't done anything with that?
- I have reseated the CPU many times... could it be the CPU or mobo are going bad? I had and used this computer for the past 1-2 years or so as a file server with no problems...

Any one ever see something like this?

Thanks!!!

Don R.

 

[KGB]

Have you properly cleared the CMOS?

What I mean is not just take the battery out.

 

[Al Neri]

good idea

 

[In2Photos]

Sounds like a PSU problem though. Can you swap it with one from another working build?

 

[Al Neri]

reset CMOS no go

im trying a PSU now