About a week ago, i did start to face a problem with my desktop computer at home. The machine was just hanging, or sometimes shutting off… after the first shuttdown, when i did try to power on the computer, i did hear a tipical “bip” serie from the CPU, and have saw the BIOS message about overheating. Ok, we are not totally blind now, we have a clue about the origin of the problem. So, i shuttdown the computer, and did start a cleanning procedure on the heat sink. I have another heat sink (used) here, but after the cleanning, i just add another thin layer of thermal grease to the heatsink, and gave it another try… no luck…

Second chance, did change the heat sink, and another try… no luck again. Now i was not much confident about the overheating, because i start to think: “two heat sinks with dissipation problems“? And we are not in summer here… The computer’s BIOS has some indicators about the CPU thermal state, and so i did look it and took note of the numbers. About 60° C, even 70°C.. i do confess i did not have any parameters. So, i did a new power on, and running against time i did install lm_sensors (excellent application, i think OpenSolaris needs something like this on x86 hardware). The only problem i did see with the ubuntu gutsy installation, was the fact that after i did try to use the gnome applet, i had to realize that i need to execute the sensors-detect perl script. The Debian rules avoid user interaction at installation time, but i think here a dialog was essential…

Now, with the gnome applet up and running, i could see the “red” alarm about overheating. The numbers were slightly different from the indicators of the system BIOS, but by the red color on the CPU temperature, i could see that something was really strange with the CPU. The CPU is a Pentium IV 3.0 Ghz, and i have a old 2.4 Ghz CPU on a “not working” motherboard, so… i did change the CPU to see if the problem was not the CPU itself. No luck again…
Ok, now i was convicted that the problem was not the CPU or the heat sink, and the problem was on the motherboard or the power supply. I was praying to be the power supply because i already have a not working motherboard, and my computer is a old one (socket 478), with 2,5Gb DDR RAM, etc… So, let’s try the power supply first!

Bingo! After remove the connectors from the motherboard, i could see that the connectors were not in a good state, and after change the power suppy… everything was working again! The gnome applet is showing 45° C on average, and the color is yellow. I did change the heat sink for a new one, and the speed is 2850 RPM on average. Last step is take note of these “normal” values to have a parameter for future situations like this.
Peace.