In message , "Dave Plowman (News)"
writes
In article ,
Ian Jackson wrote:
I had a similar thing which drove me crazy. Happened just after fitting
a new graphics card. Which was just coincidence. Turned out to be the
main processor overheating and shutting down. Its fan was working
normally and no error messages generated. Removing the heatsink,
cleaning and applying new thermo conductive paste sorted it. Now have a
spare power supply...


I had the same problem with the PC shutting down when the processor was
working hard. Its heatsink was full of dust. Soon afterwards, I again
had shutdowns. This time it was because the PSU fan had seized solid
(probably dry bearings). Freeing-off and re-lubrication with WD40 has
worked for the last 6 months (but I will fit a new fan one day).

Mine was relatively new and the heatsink clean. Plenty of fans, too, all
working. It's a home assembled one which worked fine for a year or so
before developing the symptoms. I used the paste which came with the
heatsink originally and that had gone hard - dunno why.

Unfortunately, in this house, there seems to be an inexhaustible supply
dirt and dust. God know where it comes from. You really would NOT
believe how filthy my home-made filter gets.

Actually, I forgot to mention also that the clamping of the heat
dissipater/ fan assembly to the processor was rather loose. This would
definitely have made things worse. I disassembled everything, cleaned
off the dust and thermal paste (which was still soft), did a bit of
judicious bending so the clamp was firm, put on new thermal paste, etc.
It was like a new machine when I had finished.
--
Ian