27" 2011 iMac CPU fan full blast

[Zeke D]

hello, all, I added an SSD to my 2011 27" iMac using the OWC SSD upgrade kit. After reassembling the unit (60-minute disassembly, 60-minute reassembly) the CPU fan goes full blast. I can use Mac Fan Control to set the CPU fan to the CPU heatsink, and the fan speed slows down to a decent RPM. I've checked that all the sensor cables are seated properly, and the only cable I had issue with was the right ambient sensor. The leads pulled out of the plastic end, but I replaced them and reseated it.

Any suggestions on what is causing the CPU fan to go nuts? Any other information needed to help me troubleshoot?

 

[hifoo45]

hello, all, I added an SSD to my 2011 27" iMac using the OWC SSD upgrade kit. After reassembling the unit (60-minute disassembly, 60-minute reassembly) the CPU fan goes full blast. I can use Mac Fan Control to set the CPU fan to the CPU heatsink, and the fan speed slows down to a decent RPM. I've checked that all the sensor cables are seated properly, and the only cable I had issue with was the right ambient sensor. The leads pulled out of the plastic end, but I replaced them and reseated it.

Any suggestions on what is causing the CPU fan to go nuts? Any other information needed to help me troubleshoot?

Last year I did the same exact thing (2011 SSD Upgrade) and OWC sent me the wrong thermal sensor (year 2010) so my fans also went 100% RPM. I'd make sure you have the correct year.

2010 (red and black cable) https://eshop.macsales.com/item/OWC/DIDIMACHDD09/
2011 (no red and black) https://eshop.macsales.com/item/OWC/DIDIMACHDD11/

So I contacted them and they sent the correct year and everything was gravy until my logic board failed about 9 months later

Good luck.

 

[Zeke D]

The unit they sent me was all black. I suspect that that is not the case, since I had the OEM drive in there and the same symptoms were occurring. Thanks for the tip!

Last year I did the same exact thing (2011 SSD Upgrade) and OWC sent me the wrong thermal sensor (year 2010) so my fans also went 100% RPM. I'd make sure you have the correct year.

2010 (red and black cable) https://eshop.macsales.com/item/OWC/DIDIMACHDD09/
2011 (no red and black) https://eshop.macsales.com/item/OWC/DIDIMACHDD11/

So I contacted them and they sent the correct year and everything was gravy until my logic board failed about 9 months later

Good luck.