MBA A1932 820-01521-A no Post after few seconds it restarts

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  • PACh
    Member
    • Feb 2022
    • 24
    • Austria

    #1

    MBA A1932 820-01521-A no Post after few seconds it restarts

    Hi, I need help fixing this. Any help will be highly appreciated.

    Got a macbook air A1932 820-01521-A with the trackpad click not working, the fuse was blown (its never the fuse) I tested the line and seems ok, replaced the fuse and it worked again... all good BUT when I tried to remove the board again I pressed the reset switch (SW6955) next to the battery connector WITH the USB-C power still connected to the board.... I pressed and kept pressed for some seconds twice because the fan started to spin... then I realized why.... 😕

    After that the machine wont boot, It gets 20V and start booting it goes briefly until 0.57A the returns to 0.45-0.49A and stays there, after some seconds it restarts the boot process again (watch the video), I dont get anything on the screen. the CPU start to get hot and fan starts spining, I guess it reboots because CPU gets too hot.

    The switch SW6955 still gets 3.3V
    All the SLPS2R are with the correct voltage.
    PVDDCPUAWAKE_SW0 to _SW3 when booting 0.97V then goes to 0.55V and stays there.

    PP1v2_S0SW: 1.19V
    PP1v_S0SW: 1V
    PPVCCIO_S0_CPU: 0.95V
    PPVCCSA_S0_CPU: 1.1V
    PPVCORE_S0_CPU: 0.84V
    PPVCCGT_S0_CPU: 0V
    ALL_SYSPWRGD: 1.8V

    L7210: 0.844V
    L7230: 0.844V
    L7230: 6.5 Ohms
    L7210: 6.5 Ohms
    L7430: 5 Ohms
    L7410: 5 Ohms
    L8102: 52.4 Ohms
    L7030 is 1.9Mohm

    Trackpad click still works, no green light on shift key, if I connect an usb to the usbc it gets light but not like it is reading it.

    Watch the video
  • HelpMeRepair
    Senior Member
    • Jun 2022
    • 62
    • Canada

    #2
    Re: MBA A1932 820-01521-A no Post after few seconds it restarts

    *imnub* is the keyboard ok? is the close panel switch engage?

    Comment

    • PACh
      Member
      • Feb 2022
      • 24
      • Austria

      #3
      Re: MBA A1932 820-01521-A no Post after few seconds it restarts

      Originally posted by helpmerepair
      *imnub* is the keyboard ok? Is the close panel switch engage?
      Keyboard works, i can get into DFU (tried to restore but didnt work)
      What do you mean by „close panel switch“?
      Last edited by PACh; 09-18-2022, 01:48 AM.

      Comment

      • HelpMeRepair
        Senior Member
        • Jun 2022
        • 62
        • Canada

        #4
        Re: MBA A1932 820-01521-A no Post after few seconds it restarts

        if lid not fully closed+bad kb =/

        Comment

        • HelpMeRepair
          Senior Member
          • Jun 2022
          • 62
          • Canada

          #5
          Re: MBA A1932 820-01521-A no Post after few seconds it restarts

          explenation : a clietn wit non working kb return me a fully working battery and macbook to me , i told him that if he wanted to boot the laptop he had to plug in the charger n thats it , then next day he says hey its not working my mb is dead ... he bring it i flip the mb unplug the battery and tell myself its a SMC fault.,..
          but nah , it was faulty close lid switch

          Comment

          • HelpMeRepair
            Senior Member
            • Jun 2022
            • 62
            • Canada

            #6
            Re: MBA A1932 820-01521-A no Post after few seconds it restarts

            happends only wit dead kb + bad lid sensor lol

            Comment

            • HelpMeRepair
              Senior Member
              • Jun 2022
              • 62
              • Canada

              #7
              Re: MBA A1932 820-01521-A no Post after few seconds it restarts

              sudo nvram autoboot=%03


              thats auto power on wit charger or lid up

              sudo nvram autoboot=%00

              thats only power button
              in terminal while into a session for sure hehe

              Comment

              • PACh
                Member
                • Feb 2022
                • 24
                • Austria

                #8
                Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                Originally posted by HelpMeRepair
                explenation : a clietn wit non working kb return me a fully working battery and macbook to me , i told him that if he wanted to boot the laptop he had to plug in the charger n thats it , then next day he says hey its not working my mb is dead ... he bring it i flip the mb unplug the battery and tell myself its a SMC fault.,..
                but nah , it was faulty close lid switch
                The logicboard behaves the same when I take it out with nothing but the usb-c connector. The booting amperage changes are the same and the cpu gets hot.

                Comment

                • HelpMeRepair
                  Senior Member
                  • Jun 2022
                  • 62
                  • Canada

                  #9
                  Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                  bad battery +charger might be ur answer lol

                  Comment

                  • HelpMeRepair
                    Senior Member
                    • Jun 2022
                    • 62
                    • Canada

                    #10
                    Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                    if a macbook pro a1398 dont have a good battery it goes into boot loop

                    Comment

                    • PACh
                      Member
                      • Feb 2022
                      • 24
                      • Austria

                      #11
                      Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                      Originally posted by HelpMeRepair
                      bad battery +charger might be ur answer lol
                      Tested with new battery and different working chargers…

                      Comment

                      • HelpMeRepair
                        Senior Member
                        • Jun 2022
                        • 62
                        • Canada

                        #12
                        Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                        Originally posted by PACh
                        Tested with new battery and different working chargers…
                        smc chip chek wit thermal cam for faulty chip

                        Comment

                        • HelpMeRepair
                          Senior Member
                          • Jun 2022
                          • 62
                          • Canada

                          #13
                          Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                          if u dont have drop some alchool n watch for fast drying area

                          Comment

                          • HelpMeRepair
                            Senior Member
                            • Jun 2022
                            • 62
                            • Canada

                            #14
                            Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                            if none micro circuit get hot except cpu , chek for screen defect if not ... core n ram defect ? thats what i know so far and i rmbr ya that im nub lol

                            Comment

                            • PACh
                              Member
                              • Feb 2022
                              • 24
                              • Austria

                              #15
                              Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                              Originally posted by HelpMeRepair
                              if u dont have drop some alchool n watch for fast drying area
                              Macbooks with T2 chip doesnt have SMC

                              Comment

                              • HelpMeRepair
                                Senior Member
                                • Jun 2022
                                • 62
                                • Canada

                                #16
                                Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                                i bought a flir c3 at a pawnshop 2 week ago and its alrdy not powering up XD plz god help me

                                Comment

                                • HelpMeRepair
                                  Senior Member
                                  • Jun 2022
                                  • 62
                                  • Canada

                                  #17
                                  Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                                  58-95

                                  https://imgur.com/a/NVC9Kde

                                  https://imgur.com/a/bmrIjk7
                                  38-95
                                  Last edited by HelpMeRepair; 09-18-2022, 02:16 AM.

                                  Comment

                                  • mon2
                                    Badcaps Legend
                                    • Dec 2019
                                    • 13830
                                    • Canada

                                    #18
                                    Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                                    On the A1932, post the voltage readings of:

                                    SMBUS_3V3_BATT_SCL
                                    SMBUS_3V3_BATT_SDA

                                    Comment

                                    • HelpMeRepair
                                      Senior Member
                                      • Jun 2022
                                      • 62
                                      • Canada

                                      #19
                                      Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                                      would love to , dont have acess to machine =( ( btw hows is the lion head ? hehe )

                                      Comment

                                      • HelpMeRepair
                                        Senior Member
                                        • Jun 2022
                                        • 62
                                        • Canada

                                        #20
                                        Re: MBA A1932 820-01521-A no Post after few seconds it restarts

                                        Originally posted by PACh
                                        Macbooks with T2 chip doesnt have SMC

                                        Comment

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