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A1932 820-01521 DFU mode?

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    A1932 820-01521 DFU mode?

    Hi, this A1932 820-01521 has 5V 0.60A at the input usb-c (both inputs are the same)

    PPBUS_G3H is present and all the AWAKE and SLPS2R also are ok.

    Seems that "Device stuck in DFU mode due to corrupt T2 firmware", as it is mentioned in this good link:

    https://repair.wiki/w/A1932_2018_-_2019_MacBook_Air

    I have tried to download Apple Configurator 2 from Apple Store, but the mac I used seems not good for this app. (osx high sierra)

    I have tested dfu mode state with this mac in siystem information.

    I will try to use a hackintos pc but not sure if it is possible to get this app running in this type of machines.

    Any comments will be appreciated.
    Attached Files
    Last edited by Francisco.s; 04-28-2022, 12:56 PM.

    #2
    Re: A1932 820-01521 DFU mode?

    Preferable to use the same macOS version between target and host. Or at least having older macOS on the host than the target can definitely cause issues.

    https://logi.wiki/index.php/DFU_Mode_Restore_(Macs)
    https://mrmacintosh.com/how-to-resto...into-dfu-mode/
    OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

    Comment


      #3
      Re: A1932 820-01521 DFU mode?

      Thanks piernov, I don't have another mac, and the one I am using for tests is not mine, so the best option for now, is to prepare a hackintosh with Catalina or Mojave.

      Have you tested with a hackintosh, or perhaps is better a virtual machine within windows?

      Comment


        #4
        Re: A1932 820-01521 DFU mode?

        Use at least Big Sur if possible. It should work even on unsupported Mac with patched installer and USB-A. I don't know if it works on hackintosh though but you could try at least. In a Virtual Machine USB can be unstable so I wouldn't recommend it.
        OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

        Comment


          #5
          Re: A1932 820-01521 DFU mode?

          Hi, finally could get an original macbook with big sur, then install Apple Configurator 2 from Apple Store and follow the instructios from mrmacintosh.com and could revive this board.

          Now the input voltage at usb inputs is ok. (20v)

          Have a problem with battery or charger circuit, but I'm happy seeing this thing booting. (a bit slow due to batttery not being detected)


          Thanks piernov for your help.

          Comment


            #6
            Re: A1932 820-01521 DFU mode?

            On the battery not being detected, see attached.

            SMBUS_3V3_BATT_SCL
            SMBUS_3V3_BATT_SDA


            Check the voltage on D6950 to confirm the I2C / SMBUS interface lines are not being clamped down. These points should be ~3v3 for each = lines are high impedance and the local pull-ups @ R6951 & R6952 are used to pull them to a 'soft-high'.
            Attached Files

            Comment


              #7
              Re: A1932 820-01521 DFU mode?

              Originally posted by mon2 View Post
              On the battery not being detected, see attached.

              SMBUS_3V3_BATT_SCL
              SMBUS_3V3_BATT_SDA


              Check the voltage on D6950 to confirm the I2C / SMBUS interface lines are not being clamped down. These points should be ~3v3 for each = lines are high impedance and the local pull-ups @ R6951 & R6952 are used to pull them to a 'soft-high'.
              Hi mon2, this data bus are ok.

              Have 3v pulses on both lines.

              Battery should be damaged, it has been damaged by some liquid.
              The controller chip inside battery, has disabled its output.

              Time for a new battery.

              Thanks for your help.
              Last edited by Francisco.s; 05-12-2022, 08:50 AM.

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