Anyone care to tackle this:
Brought to me because it started up in the middle of the night, and shut down when it felt like it.
Replaced broken Power switch
Replaced motherboard, CPU,heatsind, and fan.
Replaced RAM
Replaced Power Supply
Added extra case fan for cooling.
Removed Vista from SATA HD and installed XP Home
Malware Bytes finds nothing wrong
AVG also comes up clean
Now Combofix looks good also
Completely isolated everything from the case on my workbench, and it ran perfectly for about 15 hours.
Installed everything in an older case, and it ran perfectly for a number of hours also.
I made an insulating gasket of sorts from a new clear back seat floor mat to prevent any arcing from mobo solder points.
The board is a combo board, so last night I removed SATA drive and replaced with IDE drive and installed Windows XP Home.
All of this and many hours of troubleshooting and it is doing the same thing as the day it was brought to me, while it is in the original case.
It shutdown this morning while doing Windows updates on the newly installed IDE drive with fresh XP Home
Running out of ideas other than getting a new case, so ran Combofix for a fresh perspective.
Every suggestion people make to solve this headbuster is negated by the fact that the hardware is all NEW and tested, and the fact that every action
is a repeat of what was happening when it was first brought to me.
I've done the piece by piece in and out of the case one at a time, etc, ad naseum, and like I said, I'm about out of ideas.