A1502 fan not turning on

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  • myth77
    Badcaps Veteran
    • Feb 2017
    • 380
    • Croatia
    #1

    A1502 fan not turning on

    I very rarely work on macs... Received this mac, i dont know history...It seems everything is working but i have no fan spinning...I tried different fan but same thing. The problem is on FAN_RT_PWM signal... there is no voltage. On connector J6050 pin 1 and 4 voltage present, but pin 2 nothing. I checked q6060 and on r6061 the resistence seems ok. Tried nvram reset and smd reset but same thing. Also, i used the thermal camera and temperature goes to 85 C on CPU in several minutes but fan is doing nothing.
    I have only two more ideas..either q5159 or something associated with cpu thermal sensor is dead or U5000 dead!?
    Any other ideas?
    Tags: None
    • piernov
      Super Moderator
      • Jan 2016
      • 4439
      • France
      #2
      Re: A1502 fan not turning on

      On 820-4924 fan starts spinning only after CPU gets burning hot. If it's not throttling it's fine.
      OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

        Comment

        • myth77
          Badcaps Veteran
          • Feb 2017
          • 380
          • Croatia
          #3
          Re: A1502 fan not turning on

          So, you are saying 85 C is not enough for apple to turn fan on? Lol

            Comment

            • mon2
              Badcaps Legend
              • Dec 2019
              • 14666
              • Canada
              #4
              Re: A1502 fan not turning on

              What is the voltage to ground of SMC_FAN_0_CTL ?

                Comment

                • myth77
                  Badcaps Veteran
                  • Feb 2017
                  • 380
                  • Croatia
                  #5
                  Re: A1502 fan not turning on

                  Originally posted by mon2
                  What is the voltage to ground of SMC_FAN_0_CTL ?
                  0 vol

                    Comment

                    • reformatt
                      Badcaps Legend
                      • Feb 2020
                      • 1500
                      • Australia
                      #6
                      Re: A1502 fan not turning on

                      Just run diagnostics by pressing D during startup. Fan and tach is tested during the tests. Report back if you have an error.

                      Apple don't mind running the CPU's hot.

                        Comment

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