Today my PC started spontaneously shutting down every 15-30 minutes. If I left it off for a while, I could start it up and it would run for another 15-30 minutes before it would shut down. Very annoying!
I suspected it was some sort of overheating problem due to the fact it would run okay for a while once I’d given it a chance to cool down. To test this theory I downloaded a tool to monitor the CPU temperature called RealTemp. As soon as I ran this tool I could see the problem. All 4 CPU cores were running at 90 deg C, and this was while the computer was Idle. It wasn’t even a hot day, probably only about 22 deg C indoors.
I immediately powered off the PC and opened it up. I suspected that perhaps the fan used to cool the CPU had failed. This turned out to be fine, however there was a lot of dust around the heatsink. Perhaps the build-up of dust was trapping the heat in the heatsink and causing the CPU to overheat. I unmounted the fan and heatsink (You can do this by hand simply by undoing 4 clips that hold the heatsink and fan in place over the CPU) and vacuumed it to remove all dust. I also took the opportunity to completely vacuum all the dust out of the PC case – it was everywhere. I noticed that when I removed the heatsink both the CPU cover and heatsink were covered with the remnants of thermal paste. Thermal paste is used to provide a good conductive bond between the CPU and the heatsink.
I wasn’t sure if this was strictly necessary, so I scraped both the CPU and heatsink surfaces clean and replaced the heatsink and fan. I powered on the PC and ran RealTemp again. It was now showing around 70 deg C for each core. This was still way too high. It looked like the thermal paste really is needed.
So I powered off the PC and went down to my local PC store and picked up a tube of thermal paste for $9. When I got back I removed the heatsink and fan and this time applied a layer of thermal paste to the CPU cover. I then reinserted the heatsink and powered up the PC again. This time RealTemp reported the CPU temperatures at around 37 deg C. Much, much better!
I’ve been monitoring my CPU temperatures throughout the day, and during typical usage such as web browsing, the CPUs sit at just over 40 deg C.
I’ve learnt that thermal paste is not an option when mounting a heatsink to a CPU.