I think some of the sensors in this iMac9,1 are malfunctioning causing some fans to run at full speed. Years ago, fans first started running full speed intermittently but soon always did. I think it has to do with dust because i once fixed it (temporarily) by blowing and sucking with a vac. I've been having to use software to set the fans to minimum speed. I'm going to open it and clean it out soon (was going to do long time ago but never got around to do it) and put in an SSD while i'm in there. MacsFanControl doesn't show anything weird, but Psensor shows many more sensors and some appear to be malfunctioning: Video: https://a.pomf.cat/jgcoqt.mp4 The sensors are malfunctioning right? Do you think it is caused by dust? Will cleaning it solve the problem? or is there permanent damage?