My CPU fan *sometimes* indicates 0 rpm with fan at full speed
I have checked other threads regarding this issue and they suggest replacing the resistor with the "47K 1/16W 5% in a 0402 package" on digikey.
However, the issue described in other threads are about the fan constantly at full speed .
My issue is random and only happens about once a day, for about 30 seconds.
This is what happens: For no apparent reason (ie I'm not using more processing power than usual), the fan starts to rev up, a bit like car racers rev up their engines just before a race. It's goes a bit like this:
VR.... VRRRRRR.... VRR.. VRR.. VRR.. VRRRRRRRRRRRRRRRRRRRRRR
The pattern is not the same every time but it's a bit like that. (smcFanControl indicates 0 rpm during that time)
The thing is, it only happens once a day, so the resistor must still be in place (since the fan functions normally 99% of the time).
How come the issue happens only sometimes? What could be wrong?