27" 2011 iMac CPU fan full blast

Discussion in 'iMac' started by Zeke D, Jun 14, 2017.

  1. Zeke D macrumors 6502a

    Zeke D

    Joined:
    Nov 18, 2011
    Location:
    Arizona
    #1
    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?
     
  2. hifoo45 macrumors member

    Joined:
    Apr 29, 2010
    #2
    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.
     
  3. Zeke D thread starter macrumors 6502a

    Zeke D

    Joined:
    Nov 18, 2011
    Location:
    Arizona
    #3
    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!
     

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