03/12/2018
This is what happens when you don’t clean a PC for a long time. The photo shows a CPU heatsink with the fan removed (and lying at the right), and you can see that the aluminium fins are more than three-quarters blocked by a mat of lint. The fan itself and the case fan at the top are also covered in dust. What you don’t see here, because I had already hoovered it out before taking the photo, is that the rest of the case was heavy with skeins of lint and dust too. Not surprisingly, air flow was so restricted that the PC overheated within a few seconds of being switched on and immediately shut down to protect itself.
This PC had been used for around ten years without ever being cleaned, so was an extreme example. But any PC, especially if stood on a carpet, will pull dust in through its fans and need some attention every few months. Dust can be a PC killer, not only by overheating, but also because it stores static electricity which can destroy the electronics.
Cleaning a PC is a professional job, as you need compressed air and an anti-static wrist strap to prevent damage. But if you are sensible and careful, you can keep the dust at bay by regularly cleaning a PC case using the crevice tool of your hoover (not the brush). If it has got bad you will need to have it cleaned properly, but if you are very careful you can stop the dust building up in the first place. The rules:
1. Before you open the case, ground yourself and the PC. Touch some bare metal on the PC with one hand and some grounded (earthed) bare metal, e.g. water pipes, with the other. Do the same for any tools you use, e.g. hoover nozzle, and keep repeating frequently as you work.
2. Do not touch any electronic components or circuit boards either with your fingers or the hoover nozzle. Static electricity could damage it! Hoover the case, the slots and grills, cables and fan blades only. If in doubt or if you think you might accidentally touch something you shouldn't, clean the outside only.
3. Do not let fans spin uncontrolled. Hold the blades with a finger -- or a biro or cotton bud if you can't reach, e.g. if cleaning from the outside -- so they don't spin in the air flow from the hoover and damage the bearings.
4. Do not remove the CPU fan like I did in the photo unless you are sure it comes off separately from the heatsink (the fins). If you removed the entire cooler, you would have to have it refitted with special thermal paste by a specialist.
5. Do not open the power supply. There may be dangerous voltages inside even hours after being switched off.
6. If you can, remove the plastic front of the tower and clean the air filters, if it has them. Take care -- not all makes come off easily.
This applies to desktop or tower PCs. If you have a laptop, keep any grills clear, but don't go inside.
