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820-00244 PP5V_S0 shorted to ground

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    820-00244 PP5V_S0 shorted to ground

    Hi all,

    i have macbook 12" 820-00244 that came with no keyboard..
    short story..i change the flexible from trackpad to logic board and the keyboard can be use perfectly..and no it came back with no keyboard and trackpad so i tried to change again the flexible but when i try to change it maybe the cable was slented and suddenly burnt L4804 (PP5V_S0_KBD_F). so i changed L4804 and C4804..after finished i use diode mode for checking the short and found out PP5V_S0_KBD_F shorted to ground..and also PP5V_S0..

    injected 1.4V and 4A through PP5V_S0 buth nothing gets hot

    any suggestion?

    #2
    Re: 820-00244 PP5V_S0 shorted to ground

    You may have oxidation in a place. Clean the board well. Check again

    Comment


      #3
      Re: 820-00244 PP5V_S0 shorted to ground

      Originally posted by mrwab View Post
      You may have oxidation in a place. Clean the board well. Check again
      i just clean it and check there is no oxidation on the board

      Comment


        #4
        Re: 820-00244 PP5V_S0 shorted to ground

        The flex cable between the logic board and the trackpad has a special pad-to-pad pitch. The exact same or compatible cable must be used otherwise the connector contacts will short.

        Does the trackpad and keyboard work now?

        If not, what is the cable you are using? Share the part number on the cable.

        What is the history of the trackpad cable?

        Comment


          #5
          Re: 820-00244 PP5V_S0 shorted to ground

          Originally posted by mon2 View Post
          The flex cable between the logic board and the trackpad has a special pad-to-pad pitch. The exact same or compatible cable must be used otherwise the connector contacts will short.

          Does the trackpad and keyboard work now?

          If not, what is the cable you are using? Share the part number on the cable.

          What is the history of the trackpad cable?
          hi @mon2,

          right now i am not dare to turn on before i get the solution fot the short.
          actually this macbook is ex repair from another repair shop.

          here i attached the picture of flex cable.. the right one is the original..and i replace with le left one
          Attached Files

          Comment


            #6
            Re: 820-00244 PP5V_S0 shorted to ground

            Meter in resistance mode, remove all power (no adapter / no battery).

            1) What is the resistance to ground of A1, A2, B2 on U8230 ?

            2) inspect U8230 which is a small WLCSP device and if you see L4804 burnt than you had some excessive current draw (perhaps due to the trackpad cable seating).

            It is possible that U8230 is now damaged. If you feel comfortable, you could desolder U8230 to see if the short is removed. Be sure to note the pin # 1 on this very tiny device for proper placement back onto the logic board.

            When taking the measurements, remove the trackpad cable to rule out the cable & trackpad / keyboard interconnect.

            You can also consider to remove the cable @ J6799 as PP5V_S0 is linked to here (and many other locations on the logic board).

            If necessary, remove RA000 (0 ohm resistor) to isolate the PP5V_S0 rail away from the PP5V_S4RS0 rail. Only to locate the root cause of the short on PP5V_S0 rail.
            Attached Files
            Last edited by mon2; 10-29-2021, 08:57 AM.

            Comment


              #7
              Re: 820-00244 PP5V_S0 shorted to ground

              Originally posted by mon2 View Post
              Meter in resistance mode, remove all power (no adapter / no battery).

              1) What is the resistance to ground of A1, A2, B2 on U8230 ?

              2) inspect U8230 which is a small WLCSP device and if you see L4804 burnt than you had some excessive current draw (perhaps due to the trackpad cable seating).

              It is possible that U8230 is now damaged. If you feel comfortable, you could desolder U8230 to see if the short is removed. Be sure to note the pin # 1 on this very tiny device for proper placement back onto the logic board.

              When taking the measurements, remove the trackpad cable to rule out the cable & trackpad / keyboard interconnect.

              You can also consider to remove the cable @ J6799 as PP5V_S0 is linked to here (and many other locations on the logic board).

              If necessary, remove RA000 (0 ohm resistor) to isolate the PP5V_S0 rail away from the PP5V_S4RS0 rail. Only to locate the root cause of the short on PP5V_S0 rail.
              i took out RA000 and measure PP5V_S4RS0 is not shorted so the culprit must be U8230 right since PM_SLP_S3_L and PP5V_S4 not shorted.

              does anyone know which logic board that has U8230 (TPS22930)? i look around macbook 12" 820-00045 but not found

              Comment


                #8
                Re: 820-00244 PP5V_S0 shorted to ground

                With RA000 removed, which side of the RA000 pcb pads is shorted ?

                What is the resistance to ground of the output pin of U8230?

                Are you looking for U8230 to replace? So far, only found it on AliExpress.

                Comment


                  #9
                  Re: 820-00244 PP5V_S0 shorted to ground

                  Originally posted by mon2 View Post
                  With RA000 removed, which side of the RA000 pcb pads is shorted ?

                  What is the resistance to ground of the output pin of U8230?

                  Are you looking for U8230 to replace? So far, only found it on AliExpress.
                  pin 2 (PP5V_S0) that shorted.. the resistance on this pin is 0.6 ohm.

                  yes i also looking in aliexpress..only one seller sells it..
                  actually can this board turn on with PP5V_S0 shorted to ground?

                  Comment


                    #10
                    Re: 820-00244 PP5V_S0 shorted to ground

                    1) Remove R8410 & R8411 -> check if short to ground is removed.

                    2) If the short still remains, consider to flux and remove U8230.

                    Post your results.
                    Attached Files

                    Comment


                      #11
                      Re: 820-00244 PP5V_S0 shorted to ground

                      Originally posted by mon2 View Post
                      1) Remove R8410 & R8411 -> check if short to ground is removed.

                      2) If the short still remains, consider to flux and remove U8230.

                      Post your results.
                      i just remove them and still got short on PP5V_S0..PPLCDBKLT_VDDD not shorted. took out U8230 still have short..

                      Comment


                        #12
                        Re: 820-00244 PP5V_S0 shorted to ground

                        could it be C4013 that shorted?

                        Comment


                          #13
                          Re: 820-00244 PP5V_S0 shorted to ground

                          Yes if the cap is on that rail.

                          Remove it and check. If not the fault, place it back onto the board.

                          Comment


                            #14
                            Re: 820-00244 PP5V_S0 shorted to ground

                            Originally posted by mon2 View Post
                            Yes if the cap is on that rail.

                            Remove it and check. If not the fault, place it back onto the board.
                            still short..sigh

                            Comment


                              #15
                              Re: 820-00244 PP5V_S0 shorted to ground

                              Remove L4804 and check again. Perhaps the cap C4804 that follows this inductor is shorting from the repair.

                              Comment


                                #16
                                Re: 820-00244 PP5V_S0 shorted to ground

                                Originally posted by mon2 View Post
                                Remove L4804 and check again. Perhaps the cap C4804 that follows this inductor is shorting from the repair.
                                already removed but still short

                                Comment


                                  #17
                                  Re: 820-00244 PP5V_S0 shorted to ground

                                  Remove L4010 and check again if the short is removed.

                                  Comment


                                    #18
                                    Re: 820-00244 PP5V_S0 shorted to ground

                                    Originally posted by mon2 View Post
                                    Remove L4010 and check again if the short is removed.
                                    it's weird..after remove L4010 the short is gone..PP5V_S0 and PP5V_S0ALSCAM_F on L4010 both no short..

                                    Comment


                                      #19
                                      Re: 820-00244 PP5V_S0 shorted to ground

                                      Flux the pads used for L4010. Then solder back L4010.

                                      Be sure that the inductor is center on the pads. Perhaps some exposed solder mask that is causing a short.

                                      If the short comes back, leave L4010 off the logic board for now. This inductor appears to power only the camera.

                                      Then solder back the parts that were removed for this exercise. After soldering back each part, check for the short.

                                      Comment


                                        #20
                                        Re: 820-00244 PP5V_S0 shorted to ground

                                        Originally posted by mon2 View Post
                                        Flux the pads used for L4010. Then solder back L4010.

                                        Be sure that the inductor is center on the pads. Perhaps some exposed solder mask that is causing a short.

                                        If the short comes back, leave L4010 off the logic board for now. This inductor appears to power only the camera.

                                        Then solder back the parts that were removed for this exercise. After soldering back each part, check for the short.
                                        just put back L4010 and no short detected..but C1348 beside L4010 is shorted and goes straight to CPU..C1348 resistance to ground is 58.48 ohm..is it normal?

                                        Comment

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