Mac Pro 4,1 All Fans Running Full Speed

Discussion in 'Mac Pro' started by pablomanda, Dec 15, 2018.

  1. pablomanda, Dec 15, 2018
    Last edited: Dec 15, 2018

    pablomanda macrumors newbie

    Dec 15, 2018
    Hello everyone,

    I’ve a Mac Pro 4,1 flashed to 5,1 that is running constantly all the fans in full speed (very loud).

    This happens even before the booting sound.

    So I downloaded TG Pro to see if all sensors and temperatures are OK.
    I got the PS, EXHAUST AND INTAKE fans in 0 RPM. But they’ definitely spinning 100%.

    Already done SMC, PRAM/NVRAM reset with no luck. Cleaned all the dust I can see. No heavy workloads in Activity Monitor.

    Can someone help me? What’s causing the fans running full speed?

    Specs of my Mac:
    Mac Pro 4,1 (5,1 firmware)
    Radeon 5770 HD
    6GB RAM 1066Ghz
    OS X El Capitan

    Attached Files:

  2. tsialex macrumors 603


    Jun 13, 2016
    Check if backplane and tray have the same SMC version. For a 2009 Mac Pro, both have to be 1.39f5.
  3. pablomanda thread starter macrumors newbie

    Dec 15, 2018
    Oh my gosh!! I forgot to check that!!
    SMC Version (System): 1.39f5
    SMC Version (processor tray): 1.39f11

    Thank you very much tsialex!! Would you recommend me to buy a 1.39f5 tray and sell the 1.39f11 one? Thank you again.
  4. tsialex macrumors 603


    Jun 13, 2016
    I don't like at all frankenstein Mac Pros, so if I was correcting this, I'd check if the serial number for the case (check the ESN label near the video outputs) is for a 2009 Mac Pro, then I'd buy a 2009 tray.

    If it's a 2010/2012 case, I'd buy a 2010/2012 backplane.

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