Stupid fan

[thunderbunny]

Early Intel Mac Mini. The other day the fan suddenly turned onto full power which is quite noisy, and stays on as long as the power cable is connected.

Downloaded some fan utility (can't remember name) - this gives both fan readbacks as -1rpm which I'm guessing is why it's pumping full power to the fans.

Any ideas how to correct?

 

[spinnerlys]

The Mac mini only has one fan, thus the fan control software shows the second fan with -1 as RPM.
You can do the following to reset the fan speed:
Intel-based Macs: Resetting the System Management Controller (SMC)


Also have a look at Activity Monitor ( Applications / Utilities / ) and select All Processes and sort by CPU to see what the culprit may be.

image below uses sorting by CPU as an example