Gradually increasing issue with overheating

Question

So I haven't changed my computer's hardware or cleaned it in several years. I've noticed a increasing issue with temperature when I'm running CPU intensive processes, Blender, Video Games, ect.

My understanding of the problem is that the most likely cause is a build up of dust, but I've also noticed that a fan, it's actually the largest in the case isn't spinning. Now a few months ago I had to reinstall windows using rufus, but I didn't check the fan before doing that so I can't say if the fan stopped before or after doing that.

So what I want to do first is figure out why the fan isn't spinning, I'd like to see if the software is the problem before I actually look for a physical issue inside the case or replace the fan.

I checked the BIOS Monitor and it says I have only two fans, when I know for a fact I have three. I'm taking this to mean that the third is not connected.

Any advice on where to go from here? I haven't updated the BIOS yet. Fan speed reports 5 fans of which two are spinning.

Answer 1

1) Update the BIOS, and while you're there, check and adjust all BIOS settings which are temp-control related.

2) Look for temperature control apps for your (unspecified) OS.

3) If the BIOS shows fans are running optimally, clean the hardware. Dust and hair do accumulate in laptops, that cleaning the laptop also lets you look for other obstructions.

4) While you're at it, replace that failed fan.

Answer 2

Motherboard fans are generally controlled by the BIOS, or by user software installed specifically to control fans. You installed BIOS Monitor after the fact, so it's not the cause.

Find the key to press when starting the computer that will get you to the BIOS. Usually when starting, it's displayed on the monitor for a few seconds, perhaps as BIOS, perhaps as System Settings or something else. Don't worry if you miss the deadline, just restart with your finger over the key. You might be able to Google your specific PC make/model or specific motherboard make/model to discover the key to press.

Some BIOSes have advanced controls to set the speeds according to the CPU temperature or other temperature sensor inside the PC. My suggestion is to set to default for now, save settings, and start up. See if the situation improves.

Next, get some canned air. Do not use an air compressor or a vacuum. Move the PC to a dirty place like the garage or outside. Open the side and start blowing. Lots of lint and dust will come out, just keep blowing out all the nooks and crannies. You may notice the CPU heatsink has a lot of gunk in between the fins - get as much out as you can. If you notice condensation of water from the cold, slow down and blow around different places.

Last, while you have it open, trace the wire from the non-spinning fan back to the motherboard. Try unplugging and replugging it in the same spot. Note which port it's plugged into (CHA2 for Chassis 2, for instance) ; this may be useful in the BIOS.

Put it back together and turn it on. Note if the fan is spinning. If not, restart and go into the BIOS. See if there are any features specifically mentioning that specific fan port. If the setting looks like it's supposed to be spinning, the fan itself is probably dead.

Replacement PC chassis fans are cheap and usually straightforward to replace. Note the direction of the label, and which way the air blows. The replacement fan should blow in the same direction.