CPU Fan Error

Several days ago, my father's computer had a CPU fan error during its BIOS tests when he turned it on. I presumed that the fan was not functioning properly due to having collected a large amount of dust, so I opened its case and saw that the CPU fan did, indeed, have a great amount of dust. Therefore, I cleaned out the dust and restarted the computer, and the error did not reoccur. However, the next day, the error occurred again, and, that time, I was uncertain what could have caused it, so I entered the settings for the computer's BIOS and changed the power profile from "power saving" to "normal," and the error has not yet reoccurred since then.

Since I am pursuing a career in technical support, I need to be able to handle issues such as this with complete certainty and no hesitation, so the fact that I was uncertain of what to do the second time that the error occurred is not a good thing. What would anyone else here do if a CPU fan error reoccurred after cleaning the dust from the CPU fan? What advice can you offer on this subject? Thank you very much.

As someone who has been in the tech support area for many years, what you did was good. Keep in mind that the fan is probably still bad though. Dust and gunk can get up inside the fan where the coils are and even though it looks clean on the outside, it probably is not. The heat associated with the fan not being able to function properly may have also damaged the coils and it will eventually die. I personally would replace it. I have seen the 120mm exhaust fans overheat and burn out (smoke included) due to being clogged with dust bunnies and debris.

BTW: Changing the profile of the fan increased the speed to a point where it does not trip the fail sensor, but I would bet it is still not running at normal speed.

Intermittent or recurring failures usually indicate the part is approaching end of (useful) life. That fan might continue to work for months or years, with or without signalling any more errors, but it's no longer a "reliable" component you can depend on performing to rated spec. It could suddenly fail next week, and it could contribute to a thermal shutdown or damaged parts if left unattended.

Agreed with Airbozo - you did good. I never trust moving parts like fans, they're always the first things to fail in electrical/computing machinery, betcha the bearings are wearing wobbly so the magnetic tach sensor isn't registering consistent pulses. You could power it up and measure it with test instruments in or out of the system - you might find a simple problem like a wiggly connector pin or it needs a drop of precision lube - or you might find you need to fully rebuild the motor/bearing assembly - but salvaging a readily-replaced $20 component doesn't really justify spending hours of labour better spent servicing other problems, unless you're seriously bored or your budget is seriously strapped.

I like to upgrade anything that I catch failing, get a fancy high-end Noctua Industrial PPC fan or something, my logic being that if all the cheap hardware fails easily then eventually I'll only be left with fail-resistant good hardware.

If the BIOS error persists after fan replacement then you're probably looking at an underrated PSU or a motherboard VRM fault. Or "bad" and "buggy" BIOS code, lol, it happens.

(An interesting aside: I work with mechanical engineers, and they insist that mechanical components always outlast non-mechanical components, their first instinct is to blame all failures on electrical components or bad software.)