CPU Fan not spinning

[Sephinel]

For a while, my CPU fan had been sometimes spinning very slowly and making a strange sound when that happened. A couple days ago the CPU fan completely broke and was only spinning at maybe 100 RPM, then completely stopped. I tried resetting my bios and trying out different headers and the fan simply wouldn't spin anymore so I figured the fan was broken. I bought a new heatsink entirely and plugged it in today, only to find out that the new fan won't spin either. Considering resetting bios to factory defaults, trying out other headers (that I can confirm work with normal fans) and even testing out a whole different CPU Fan didn't work, I have absolutely no idea what the issue could be. Sometimes on start up the CPU Fan would rotate maybe 1/4 of a spin then stop right away, but usually no response whatsoever from the fan. Physically rotating the fan with my finger works just fine so nothing blocking it. Everything else works just fine. Any ideas?

 

[i7Baby]

Blow it out with compressed air. If that doesn't fix it then replace it.

 

[Sephinel]

Did a full compressed air cleaning when changing the heatsink, and this is a brand new heatsink/fan combo. I suppose it's possible, but I find it unlikely for the brand new CPU fan to be broken as well.

 

[i7Baby]

Just about every thread here is to do with an unlikely fault.

Try running it straight from the PSU. If that works, then replace your motherboard.

 

[Neutr1n0]

Did you check cpu fan profile/settings in bios? Could be set very low (like 20%) and it's not uncommon for fans to not run at the lowest setting. Even my noctua fans only start running on 30%.

 

[Sephinel]

Fixed it. Was a specific issue with the heatsink I had (Arctic Cooling Freezer 7 Pro Rev. 2). Had to push the fan back into place as it was a bit off. So the old heatsink broke, this one just had a small issue I had to fix.