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MacBook Apro 16" A2141 Just 5,181Volt

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    MacBook Apro 16" A2141 Just 5,181Volt

    Hi, I have a MacBook Pro 16" it has liquid damage. With the power supply I only get 5.181 volts only on one USB-C plug! Left and right. See pictures.
    Attached Files

    #2
    Re: MacBook Apro 16" A2141 Just 5,181Volt

    Remove all power. Meter in lowest resistance mode.

    Confirm the resistance across each of the 4 fuses on this logic board for the Type C connectors.
    Attached Files

    Comment


      #3
      Re: MacBook Apro 16" A2141 Just 5,181Volt

      all 4 fuses 0.37 ohm from pin1 to pin2

      Comment


        #4
        Re: MacBook Apro 16" A2141 Just 5,181Volt

        Good.

        Check the voltage @ F7000 / F7001 = PPBUS_G3H with the adapter mated with a working port.

        Comment


          #5
          Re: MacBook Apro 16" A2141 Just 5,181Volt

          0,0004v

          Comment


            #6
            Re: MacBook Apro 16" A2141 Just 5,181Volt

            So PPBUS_G3H is not working. Meter in resistance mode. Remove all power.

            Check the resistance to ground on both sides of the fuse @ F7000.

            Comment


              #7
              Re: MacBook Apro 16" A2141 Just 5,181Volt

              I should have clarified...do you see the same voltage on either side of fuse F7000 ?

              Comment


                #8
                Re: MacBook Apro 16" A2141 Just 5,181Volt

                yes
                and F7000/ F7001 is 0,35 ohms both sides to ground

                Comment


                  #9
                  Re: MacBook Apro 16" A2141 Just 5,181Volt

                  the new MacBooks always only have 5 volts after liquid or the display doesn't work! Apple built it that way on purpose!?

                  Comment


                    #10
                    Re: MacBook Apro 16" A2141 Just 5,181Volt

                    LOL.

                    Remove both F7000 and F7001 fuses off the logic board.

                    No power to the logic board.

                    Measure the resistance to ground again using the fuse pads. We wish to know, is the short to ground on the power rail producer side or consumer side.

                    Post the measurements.

                    Comment


                      #11
                      Re: MacBook Apro 16" A2141 Just 5,181Volt

                      Hi mon2, we have 11,5m ohms at pin1 and 0,35ohms at pin2

                      Comment


                        #12
                        Re: MacBook Apro 16" A2141 Just 5,181Volt

                        I absolutely have to get books to teach SMD Technink.

                        Comment


                          #13
                          Re: MacBook Apro 16" A2141 Just 5,181Volt

                          we have 11,5m ohms at pin1 and 0,35ohms at pin2
                          So the producer side = U7000 is ok with the very high resistance.

                          The fault is on the consumer side of this power rail due to the very low resistance on SMD pad # 2.

                          Confirm there are no shorts from this fuse removal and apply power again.

                          Meter in voltage mode -> check the voltage @ SMD pad # 1.

                          What voltage do you read with the meter ?

                          If this does not equal to PPBUS_G3H then most likely, U7000 is defective but need to do other checks.

                          Then, need to review where is the possible part that is shorted on this logic board. Voltage injection may be a good choice @ 0v8 with a power supply but wait till we confirm U7000 first.

                          Comment


                            #14
                            Re: MacBook Apro 16" A2141 Just 5,181Volt

                            We have at Pin1= 12.227 volts
                            Pin2=0Volt

                            Comment


                              #15
                              Re: MacBook Apro 16" A2141 Just 5,181Volt

                              Originally posted by Strolch View Post
                              We have at Pin1= 12.227 volts
                              Pin2=0Volt
                              Pictures
                              Attached Files

                              Comment


                                #16
                                Re: MacBook Apro 16" A2141 Just 5,181Volt

                                Very good. Your U7000 appears to be alive but gets shutdown due to the excessive current draw from the low resistance = 0.35 ohms.

                                Short is downstream. Would you have a current limited power supply ?

                                Dial up 0v8 = 0.8 volts and try @ 2A and inject this onto pad # 2. This is because something downstream that is shorted. It could be a capacitor or perhaps a chip.

                                Using alcohol / thermal camera - review which part gets hot. Leave the voltage low (on purpose) so to not kill a low voltage device that may be shorted to this rail.

                                Suggest to apply the voltage and then remove and check for any warming of a component on the board. If required, increase the current but go slowly.

                                Comment


                                  #17
                                  Re: MacBook Apro 16" A2141 Just 5,181Volt

                                  Unfortunately, I don't have a current-limited power supply. what does it look like? Then I'll buy it ;-). But I hope we can do it without now.

                                  Comment


                                    #18
                                    Re: MacBook Apro 16" A2141 Just 5,181Volt

                                    Do you have a variable power supply ? Need to keep the voltage low - just in case there is a short downstream to a sensitive component.

                                    Suspecting a shorted tantalum capacitor but we do not know at this time.

                                    If yes to the adjustable power supply - select at 0.8 volt (we want to keep it under 1 volt) for now. Then check for any part that is getting warm / hot to the touch or can mist alcohol. It is safe to pour alcohol over the parts you suspect and check for a quick dry of the liquid.

                                    Red power supply lead on fuse pad # 2 (the one with the low resistance) + black power supply lead to ground.

                                    Comment


                                      #19
                                      Re: MacBook Apro 16" A2141 Just 5,181Volt

                                      No I have not current limited power supply and thermal camera. But I will buy it today!

                                      Comment


                                        #20
                                        Re: MacBook Apro 16" A2141 Just 5,181Volt

                                        Power Supplies are very cheap and very effective in finding a short. I would totally invest in one!
                                        sigpic
                                        MEOWING IN THE IMPOSSIBLE UNIVERSE!

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