Dave Plowman (News) wrote:
In article ,
Tim Downie wrote:
If it was something overheating it would more likely crash than
switch itself off,. Same goes for memory faults.

In my experience, a sudden switch-off is quite common with processor
over-heating so don't rule it out.

It can happen seconds after a cold start. And the machine is well
cooled, with the correct fan on the processor which is working
normally. Thing is sometimes the PC is in use all day without
problems.

Dave,

Perhaps a silly question.

Is the PC 'hidden' away in a cupboard under the desk - or enclosed in some
other way.

Reason for the question: My other half has her computer in a side cupboard
under her desk and she was having exactly the same problems for around 6
months giving all the classic signs of overheating and shutting down.

I tried reseating everything in on the motherboard - including using paste
on the processor and moved all the cables out of the way of the airflow etc
to no avail. (A higher output PSU had also been fitted).

It turned out that the air from the fan was hitting the back of the cupboard
and was 'bouncing' around and being recirculated through the computer case
causing the processor to overheat rather quickly - some very drastic surgery
to the board at the back of the cupboard allowed the air to escape into a
large void and the problem was solved - no unexplained shut-downs now for
almost a year.

This may not be your problem, but the cause may be just as improbable :-)

HTH

BRG