My a1278 macbook pro's fan started running full speed while I was using a few weeks ago.
All temperatures look ok using iStat.
I have tried:
Any ideas?
The fan will run at high speed whenever a sensor is not responding correctly in order to protect the Mac from overheating.
Run the Apple Diagnostics to see if any hardware issues are detected.
The fan will run at high speed whenever a sensor is not responding correctly in order to protect the Mac from overheating.
Run the Apple Diagnostics to see if any hardware issues are detected.
I ran Apple Diagnostics before changing the battery and fan with the following results:
Fan and battery were replaced and fans are still running at high speed.
If you replaced the fan with a known good fan, then it would imply the issue is most likely due to a bad Logic Board or maybe the fan connector is not completely seated.
A1278 Macbook pro fan running full speed from boot
