Bypassing the HDD Fan When Installing an SSD

Discussion in 'iMac' started by Kirkle, Aug 17, 2014.

  1. Kirkle macrumors member

    Joined:
    Nov 29, 2012
    #1
    There is a thread, maybe more than one, on this site about how to deal with fan issues (the fan running at full speed) after installing an SSD.

    The problem with this topic is that it seems every post on this subject is about two to three years old. Also now if you bring up the subject everyone will tell you about one of a few software solutions.

    So what I'm wondering about is how to by pass the HDD fan sensor on a late-2012 27-inch iMac. I have heard that you can short the sensor and by doing that bypass the fan problems (since this is what Apple does when they install an SSD.

    But I have never seen a picture of this before. Or an explanation of specifically how to do it.

    Any information about how to bypass the HDD fan sensor with a hardware solution (please no software solutions), would be greatly appreciated.
     
  2. SandboxGeneral Moderator

    SandboxGeneral

    Staff Member

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    #2
    I don't know what the sensor looks like on a 2012 iMac. But on my 2010 iMac, I took the controller board from a bad HDD and plugged the temp sensor into it and used two-sided tape to stick it to the SSD. Works like a charm and the fan stays at about 1100 rpms without the need for software control.
     
  3. flopticalcube macrumors G4

    flopticalcube

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    In the velcro closure of America's Hat
    #3
    Since 2011 Apple uses the on-board thermal sensor of the drive and communicates the thermal information via pins 2 and 7 of the SATA power cable. The usual technique (and what Apple itself does) is to short these pins together with a wire.

    Here is a visual for a 2011 iMac. http://forum.hardmac.com/index.php?showtopic=10302
     
  4. Kyle-K macrumors regular

    Kyle-K

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    Aug 23, 2014
    Location:
    Geraldton, Western Australia.
    #4
    I wouldn't recommend bypassing the sensor or shorting it out, I would recommend using the external sensor available from OWC or if you don't want to spend the additional money use a software program to control the fans directly there's several available.
     
  5. flopticalcube macrumors G4

    flopticalcube

    Joined:
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    #5
    For an SSD, bypassing is fine since it doesn't generate much heat.
     
  6. Kyle-K, Aug 24, 2014
    Last edited: Aug 24, 2014

    Kyle-K macrumors regular

    Kyle-K

    Joined:
    Aug 23, 2014
    Location:
    Geraldton, Western Australia.
    #6
    While I agree regarding the heat, Personally I wouldn't do the method you have outlined above and I would just choose to do it in software. OP didn't want a software solution so I provided an alternative hardware method.

    In the end I be curious to know what solution the OP chose.
     

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