Chosen Solution
Really hope someone can help me with this, as I’ve tried all the options I can think off! So, I upgraded my 2010 iMac 27 with an i7 CPU & added a 120GB SSD as a boot drive using OWC’s Thermal Sensor Kit. For the first month, everything worked fine, however, one day as soon as I turned the iMac on, I just started hearing really loud fan noise & couldn’t figure out why. I opened the system & checked every cable, but no joy! Finally contacted OWC technical support, they couldn’t figure it out either & sent a replacement kit 3 times thinking there could be a faulty sensor cable, but the problem still persists. I also tired SSD Fan Control & iSat fan control apps, that has made no difference in the fan speed! I am really not sure what else I could try? Any suggestions, please? Not sure if this would make any difference, but it’s mainly the left fan which makes the loud noise. Appreciate any help. Thanks.
Sounds like your system is in Safe Mode. This is when SMC perceives a failed sensor which could be either a thermal sensor or a voltage sensor. While the OWC in-line sensor is one of the sensors, it sounds more like you have a different one failing here. Can you run the onboard diagnostics? Restart your system and press the D key. Depending on your OS you might get a EFI error.
