I've noticed for a couple of weeks now, my computer's exhaust case fan , (not sure on diameter), has been exhibiting strange behaviour.
This includes; unusually low RPM (from POST, it goes from 0-30-and so on progressively to 1130, then after much idle work for the system (web browsing and such), falls back to the 700-800 zone), and even now, the fan does not spin at all.
I have another 120mm case fan as an intake, running well, however it is only this exhaust fan that has been playing up. I used to see 1170 idle speeds, and 2450 rpm top speeds for this fan while heavy loads on the system.
As another detail, this fan is also definitely the loudest out of all of the fans in my system, especially at low speeds.
My other fans; CPU (running fine at 2228 RPM last time I checked), my Graphics card's fan (idles at 42/50% [950rpm] and maxes at 100% [2570 rpm] although gets stuck at 100% till next reboot) and intake (as mentioned before, yet is not plugged into Motherboard and is Molex powered) are functioning absolutely fine.
Is it possible to rectify this issue, or better the system by buying a replacement fan that is much quieter?
Thanks in advance.