Crashing HP/Compaq PC

This is my Moms pc

Compaq SR2038X With

AMD Athlon 64x2 3800+ 2GHz
2GB DDR2 RAM
250GB Hard Dive
Windows XP Media Center Edition 2005
XFX GeForce 8600 GT

Here is what happens

She Plays Second Life and the PC locks up after some amount of time. Sometimes it crahses within 10 minutes sometimes 2 Hours or more.

Here is what I've done

Checked ram with memtest86+ Ram is ok
Pulled out video card and used onboard video no help
Temps are all ok.
PSU has 12.80 Volts on 12volt rail checked with multimeter. Didn't check other rails.

Seems like when the PC is idle it's ok for a long period of time tho it has crashed on lie use such as web browsing.

I've come up with it's a failing Motherboard, PSU or CPU

Any ideas?

 

This issue is weird

I ran Prime 95 for 4 hours no crahses however when I have alot of windows open it crashes within minutes.

 

My mother had the same problem with her pc, all temps seemed fine, but it turned out they weren't, her pc sat inside a small cubicle in her pc desk, manufactured that way for the tower of course, but it was too small a space, once the cpu temp hit warning level that was set in the bios it would shut down, without leaving an event log or any trace of it being heat related.

Point being i guess is to make sure its not sitting in any type of confinement thats restricting the cool airflow, it may be getting air, but, it may be recycling hot air causing the mobo temp sensor to trip.

 

It's on a table with plenty of of air circulation.

 

Check the error log to begin with. Playing guessing game is not going to tell you, since none of us have access to look at the logs to see why the system is failing.

 

Well the game doesn't have an error log the system just freezes up so I don't think there would be an error log for this.

 

Motherboard died. WIll not post now

 

Double check the power to the mobo? maybe a bad connection in the 20/4 plug

 

The error log is a part of XP, not the game. If the Mother board died, then that means that the CPU is toast. With the cost of machines now days, you can replace with a new one for around $500.00.

 

Yes but It was doing weird stuff like I had no USB at all whatsoever. I think the CPU is still ok doesn't necessarily mean the CPU is dead

 

I figured out there is a short on my motherboard.

Somtimes it won't post at all. Sometimes posts fine and sometimes beeps and I looked up that error code and it meant motherboard issue. Somtimes says my CPU fan as failed but it's running. The case fan header on the board is also shot. Fan works fine but it won't power on plugged into the case fan header on the motherboard.