Chosen Solution
After a power outage last night, when my iMac was running, it was obviously suddenly powered down. This morning I turned it on and had to wait a considerable time for it the complete its restart process (40minutes). When I logged on I noticed that the fans are running at full blast. Why has this happened and how do I reset the fans to run at their correct speed?
I’m suspecting something gave out from the surge. Did you have the system plugged into a good surge suppressor or a UPS? Both help protect your system from damage from surges and in the case of the UPS it can back fill low voltage condition (not all UPS’s do this). Can you run this app to see whats happening with the fans TG Pro
