I have a MacBook Pro (Retina) and I am noticing that the fan is not running at all even though the temperature gets to more than 60c and the system starts lagging. I had iStat Menu installed and when I switched from default to manual setting and set the speed the fan would start spinning.
Now I am using the manual setting and running it on 4000rpm and the temperature gets to between 40c-50c. I am concerned about why this is happening? Why does it not work automatically on the default setting even though it gets so hot to the point that it starts to lag. Is it a software bug or does my fan have some sort of hardware issue?
One more thing: when I adjust the fan speed slider from 4000 to 2000rpm the fan suddenly stops working and I can not hear any sound and the temperature starts to heat up.
I also uninstalled the iStat Menu to see if it makes a difference, but the fan still doesn't run no matter how hot the laptop gets. Please advise the possible solution to this problem.
I am running Mac OSX 10.11.
P.S. Sorry for my bad English.