Here's what to do if your CPU's cooling fan is making a racket
QUESTION My PC is usually quiet, but it has recently begun making a horrible scraping and whirring noise. I have traced this to the fan on my CPU cooler, a Thermalright MUX-120. Can I replace the fan without having to buy an expensive new cooler?
HELPROOM ANSWER Yes, you can. Unlike most stock processor coolers the Thermalright MUX-120 is designed to use a standard 120mm fan, which is attached to the heatsink with a pair of clips. Thermalright offers a selection of 120mm fans on its website, although not the particular model for your cooler. It may be worth contacting the firm to ask which fan is the appropriate replacement.
Alternatively, you could buy a compatible fan of your own choice and simply clip it to the heatsink using the existing clips. To match the performance of the original fan, you will need to look for a replacement 120mm model that delivers at least 41.8cfm of airflow; if you want it to be just as quiet, look for a noise level of 23.5dBA or lower.
Any other readers who are suffering a noisy PC should check their fans. A noisy fan is unlikely to provide adequate cooling and may result in costly system failure if the components are allowed to overheat, particularly the processor.
Replacing the case fans is usually easy; they generally come in standard sizes and are simple to swap out. If you check your fan for a part number, you should be able to find the full specification online and find an inexpensive equivalent.
Make sure the power connector matches that of your original fan. You'll often find a quieter fan is available as an upgrade, which can make a big difference to the overall amount of noise created by the PC. Quiet PC is a good place to begin your search.
Most PC owners who have a failing CPU cooler fan won't be so lucky, since the fan is often a custom-designed part of the cooler, meaning the entire unit must be replaced. This can be a more complicated procedure than just replacing the fan. However, with many standard CPU coolers you can buy an identical replacement, then remove and fit to your existing heatsink the new fan.