Chosen Solution
Hi community, One day after a long storage time I switched on my MacBook Pro 13" 2020 (A2251) and the left fan was on at full blast all the time — even with the machine switched off. The fan (usually 8881 rpm) only switches off when the machine goes completely out of battery. I tried SMC and PRAM reset to no avail, reinstalling the operating system didn’t help, etc etc. I downloaded MacsFanControl but I can’t reduce the speed or switch off the fan using the software (btw, right fan is ok, usually at 0 rpm—maybe to compensate—but can be controlled ok using MacsFanControl). The laptop just went out of warranty and I would like to avoid bringing it in for repair. I am no expert but it feels like there must be some physical component (like a transistor) that has some issue. There was no water spillage whatsoever (not that I remember of at least), I just left the computer stored in a drawer inside its laptop case (protected from dust) for a few months while on parental leave. However, the computer was stored under a heavy pile of paper sheets (maybe 3-4 pounds). I’m unsure this could have caused the problem. Could a fan replacement help? I am not convinced of this option because the fan is actually working, what is not working is the control of the fan speed. Any input is welcome!! Thanks in advance you all, sil
Hi Has the device been dropped? It might be a dodgy connection for the fan! I would try disconnecting it and reconnecting it It could be a verity of other things though Thanks:-)
Hi Sil Yes, this does sound like a physical issue, because if you can still turn on your Mac, it sounds like a faulty component. Try getting a new fan first and see what happens. Also, if you have been using it for a long time, a component might have over heated. I am not 100% sure, though.
@silsil Did you get your system wet? Corrosion damage on the logic board could be a cause or its time to replace the fan! MacBook Pro 13" (A2251, 2020) Left Fan There is a feedback circuit which uses a tach to measure the fan’s RPM’s it could be damaged or the logic board speed control circuit has issues.
Update: I went to the local Apple Store and the person who helped me was able to solve the issue by just disconnecting and reconnecting fans and battery (and free of charge!). He said the connectors were securely in place, so maybe by unplugging the battery something got reset in the circuit (something that had not been fixed by SMC/PRAM reset). @hellomacos your original advice turned out to be the solution! Thanks you all :)
