I have a machine with a Pentium 4 CPU in it that I run as a server. I've used it for a long time with no issues. Recently it has been unable to run for more than about 3/4 minutes from a cold-boot before locking up. My syslog shows that my CPU is overheating badly.
Upon inspection of the case there was some small amount of dust, but nothing massive, and the problem continues despite a thorough cleaning (including removal of heatsink and CPU to check for anything at all that could be causing this).
I'm really stuck for ideas on how to diagnose what is happening. Any ideas much appreciated!