Help! My Sony PIII spontaneously shuts off after 45min of operation

I have a Sony PIII running Win98 which about 2 months ago started
shutting of spontaneously after 45 min of operation. I had the power
supply checked and it checks okay, the power supply fan and processor
fan check okay. The monitor I have had connected to the computer
about 2 years started having a wavy line at the top of the monitor on
each side, the printer I have connected to it works just fine.
Any ideas on why the machine spontaneously shuts off?

(Sheila Villa) wrote in message news:<. com>...
> I have a Sony PIII running Win98 which about 2 months ago started
> shutting of spontaneously after 45 min of operation. I had the power
> supply checked and it checks okay, the power supply fan and processor
> fan check okay. The monitor I have had connected to the computer
> about 2 years started having a wavy line at the top of the monitor on
> each side, the printer I have connected to it works just fine.
> Any ideas on why the machine spontaneously shuts off?

Advice: first check BIOS for overheating controls. Most modern
systems, pIII or later, will have overheating protection, which might
make the computer auto-shutdown. if 6there is such an option try
shutting it off. also, if you haven't already, blow dust off the
motherboard and out of the power supply, and anywhere else there might
be dust. dust can cause overheating, and sometimes short components
(the latter isnot your case, but it has happened to me once)