Mid 2011 Mini Mac fan always running at full speed

Discussion in 'Mac mini' started by InVision, Dec 9, 2015.

  1. InVision macrumors newbie

    Jan 11, 2009
    I replaced the 500 GB OEM hard drive with a 480 SSD on my wife's mini mac. Installation went fine but the fan is always on full speed. There were no thermal sensors on the old drive and I followed the OWC install video step by step. I went back and checked everything step by step and no issues on connectors. Install was reasonably easy. Here the weird thing. I put on a SMC fan control app and the fan still runs at full speed.

    Any ideas would be greatly appreciated.

    Thank you,

  2. MacRobert10 macrumors 6502

    Nov 24, 2012
    If you haven't already tried this, disable the SMC fan control application and try resetting the SMC controller:


    You may also need to reset the NVRAM in case the system isn't fully recognizing the new drive:


    You might just be in some kind of loop where mds is re-indexing the new drive, in which case the problem might clear up on it's own. Otherwise maybe you need to open the unit up and check all the connections and make sure the heat sink hasn't come off. I'm not entirely certain that the SMC fan control applications necessarily work with every Mac (I don't know).
  3. InVision thread starter macrumors newbie

    Jan 11, 2009
    Well there is no heat sink on drive and no wiring I can see.

    Thanks for the reply !!

  4. George Dawes macrumors 6502a

    George Dawes

    Jul 17, 2014
    My 2011 has gone kaput - the video card is knackered , apparently it's a known issue abut crapple won't acknowledge for fear of another lawsuit

    less than 5 years and it's had it - not impressed
  5. MacRobert10 macrumors 6502

    Nov 24, 2012
    I meant that possibly you might have bumped the heat sink on the CPU while working on it. It's not likely, but still possible.
  6. wickedpapercut macrumors member


    Jul 17, 2005
    Check that the fan connector has been reconnected to the logic board correctly. It's a delicate little connector and it's easy to get it aligned incorrectly or not snapped down entirely.

    Second thing I'd suspect would be the heat sensor on the CPU. You didn't mention if you replaced the upper or lower drive. One of them requires the entire logic board to be pulled out of the mini case while the other one requires very little disassembly (I forget which is which). Anyway, if you happened to bump, dislodge, or damage the CPU heat sensor it could be creating false readings and the fan is working overtime for no reason.

    You also didn't mention the actual temperature of your CPU. Is your machine's CPU getting hot -- meaning 85+ degrees C?

    Last thought, try the free utility Macs Fan Control at crystalidea.com. It will show you several temperature sensors as well as giving some control over fan speed.

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