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Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview included)

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    Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview included)

    I have a Macbook pro 2015 model A1502
    Board 820-4924-A

    Liquid damage, not much corrotion, cleaned with consciousness and isopropyl

    Only boot in SMC Bypass (battery, charger, trackpad and LCD connected)

    In this mode booting is slow, fan is full ON, but works fine and the mac stays on.

    Dont recognize the battery, AND no boot in SMC bypass if the battery is not connected


    My charger is an original apple magsafe 45w 14.85v 3.05a. (I dont have any other, but is the charger used in that macbook for about 2 years without any problem)

    If I test without case, just motherboard, fan and charger: green light, then orange light.

    Stays with orange light, fan OFF. No heat.

    Measures:

    ppbus_g3h - 11.40v
    PP3V42_G3H - 3.12v
    PPVRTC_G3H - 3.1v
    PP5V_S5 - 4.9v
    PP5V_S3 - 0v
    PP5V_S0 - 0v
    SMC_LID - 1.98v
    PP3V3_S5 - 3.1v

    In add, yesterday found a component near the lcd connector, that cant remind what it is... Measured around 6v then 12v then 0v then 6v again and repeat.

    In other hand I have a cap C1031 470uf CRITICAL, apparently in short. An smd tester shows me a short, this is the only one grand cap what I cant measure with tester without obtain a short, all other grand caps measure like the schematic and I not see any like this.

    I think you can help me to solve this maze
    Please, and thanks for read.

    (I have tools, flux and soldering station to work in this board, and I can measure all other components and rails if needed.)
    Attached Files

    #2
    Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

    Remove the display.

    Confirm the following again,

    PP3V42_G3H - 3.12v ??

    That is too low. It should be 3v42 or close to this value.

    Power down, use meter in resistance mode.

    Black probe on ground. Red probe on this output rail.

    What is the resistance? No power during this test!!

    Comment


      #3
      Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

      Sorry, all measures are wrong because im using a needle tester for voltages resistances and consumptions. Calibration error.

      Here we go again:

      ppbus_g3h - 12.90v
      PP3V42_G3H - 3.42v
      PPVRTC_G3H - 3.4v
      PP5V_S5 - 5.18v
      PP5V_S3 - 0v
      PP5V_S0 - 0v
      SMC_LID - 2.22v
      PP3V3_S5 - 3.4v

      Double checked, my apologies...

      Comment


        #4
        Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

        Originally posted by luel View Post
        In other hand I have a cap C1031 470uf CRITICAL, apparently in short. An smd tester shows me a short, this is the only one grand cap what I cant measure with tester without obtain a short, all other grand caps measure like the schematic and I not see any like this.
        C1031 is on CPU VCORE line, its normal to see low resistance. Where was liquid damage located on the board? Can you upload a picture.

        Comment


          #5
          Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

          PP3V42_G3H

          Using smd mini tester in resistance mode, pin 1 on c1950 shows 5.19 kohms
          Tester inverted, pin 1 on c1950 shows 82.4 kohms

          Using needle tester it shows 1
          Attached Files

          Comment


            #6
            Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

            Originally posted by Spider1211 View Post
            C1031 is on CPU VCORE line, its normal to see low resistance. Where was liquid damage located on the board? Can you upload a picture.
            Uploaded a capture of the c1031

            Do you wanna that ? or a general picture of the board?
            Has been wet on the upside near the battery and otherside also.

            CPU and RAM were safe, I guess...
            When I see that, case open, disconnect battery and cry...

            Comment


              #7
              Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

              A picture of the SMD Tester
              Attached Files

              Comment


                #8
                Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                Picture of the board (Both sides), especially where there was water. Do you have a bench power supply? If yes, what is the current draw of the board?

                Comment


                  #9
                  Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                  If I put the board on the case, whit battery (completely discharged) and magsafe, screen shows charging but never boots up. If I try to power on, shows charging battery.

                  Just boot in SMC bypass, without recognize the battery, load OS and stay ON. All works. That make me think was the problem can be fixed...

                  I need to replace a knob in the power supply to use in this. If I can solve without external power supply will be good
                  Attached Files

                  Comment


                    #10
                    Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                    What do you mean with this?

                    "If yes, what is the current draw of the board?"

                    Its to measure consumption? Inject voltage? Or just replace the magsafe?

                    Comment


                      #11
                      Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                      https://www.badcaps.net/forum/showthread.php?t=88758
                      Always make sure the correct AC adapter was used with the machine. Genuine original AC adapter of the correct brand and correct power rating. Even if the connector is correct, it doesn't mean it will work and it can even damage the machine.
                      https://support.apple.com/en-us/HT201700#magsafe2
                      MagSafe 2

                      60W MagSafe power adapter with MagSafe 2 style connector

                      13-inch MacBook Pro models introduced in 2012 through 2015
                      OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                      Comment


                        #12
                        Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                        Its not the recommended charger for this laptop, I know... But is the charger I used for two years until the liquid damage.

                        It should reach the function as well... Or not? The charger is not the problem here, damage is for liquid!

                        Comment


                          #13
                          Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                          You have an issue with the battery and the AC adapter is the wrong one. If both power sources for the machine are a potential problem there's surely no point in messing with the board.
                          OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                          Comment


                            #14
                            Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                            Today I tried with another original magsafe 2 60w. Only boot in SMC bypass, and Starts without battery on SMC bypass. Fast orange light, then green light (for about 2 seconds), then orange light and stays here.

                            Measures:
                            --------------------------------------------------------------------------
                            PPBUS_G3H - 12.9v
                            R3080 pin 1 --> PPBUS_G3H 12.9v
                            R3080 pin 2 --> TBTBST_PWREN_DIV_L 8.4v
                            C3080 pin 1 --> PPBUS_G3H 12.9v
                            C3080 pin 2 --> TBTBST_PWREN_DIV_L 8.4v

                            I see some brown in Q3080 surface
                            Q3080 pin 1 --> TBTBST_PWREN_DIV_L 8.4v
                            Q3080 pin 2 and 3 --> PPVIN_SW_TBTBST 0.5v (TP1-R3088-R3091 shows a peak on 0.1v and goes down to 0.05v then stays
                            here)
                            Q3080 pin 4 --> PPBUS_G3H 12.9v

                            L3095 pin 1 --> PPVIN_SW_TBTBST 0.1v to 0.5v stable
                            L3095 pin 2 --> TBTBST_BOOST 0.1v to 0.5v stable
                            C3091 pin 1 --> PPVIN_SW_TBTBST 0.1v to 0.5v stable
                            C3091 pin 2 --> GND
                            C3090 pin 1 --> PPVIN_SW_TBTBST 0.1v to 0.5v stable
                            C3090 pin 2 --> GND

                            PP3V42_G3H - 3.42v
                            PPVRTC_G3H - 3.4v
                            PP5V_S5 - 5.18v
                            PP5V_S3 - 0v
                            PP5V_S0 - 0v
                            SMC_LID - 2.22v
                            PP3V3_S5 - 3.38v

                            Comment


                              #15
                              Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                              Pm_batlow_l?
                              OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                              Comment


                                #16
                                Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                                PM_BATLOW_L

                                TP1 --> peak on 0.0875 then goes down to 0.035v (stable at 0.035v)

                                R1410 pin 2 --> PM_BATLOW_L --> peak on 0.0875v then goes down to 0.035v (stable at 0.035v)
                                R1410 pin 1 --> PP3V3_S5 --> 3.38v

                                Q3000 pin 1 --> PP3V3_S4_TBT --> 0v
                                Q3000 pin 2 --> TBT_BATLOW_L --> 0v
                                Q3000 pin 3 --> PM_BATLOW_L --> peak on 0.0875v then goes down to 0.035v (stable at 0.035v)

                                Comment


                                  #17
                                  Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                                  Piernov has a point. You need a 60W OEM charger. I highly recommend you do this now. Stop using the 45W (even after 2 years) doesn't matter what you believe and or if it works, you need to use the proper wattage for these MacBooks to function properly. I HIGHLY recommend you get a 60W before going further trying to diagnose your laptop. AGAIN I REPEAT, do not get a 60W Amazon charger, You have to use an APPLE 60W MagSafe 2 OEM Genuine Charger.
                                  sigpic
                                  MEOWING IN THE IMPOSSIBLE UNIVERSE!

                                  Comment


                                    #18
                                    Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                                    First, thanks for your time to read and help me.

                                    YES, the charger used for the last measures is an APPLE 60Watts MagSafe 2 OEM and genuine.

                                    If I want to fix this board, I need to respect the steps of your guide. So, I will not lie.

                                    Reading a lot of threads and posts about Macbooks boards, I understand that is absolutely necessary. For this reason, I had to search a 60w Apple MagSafe and come here again.


                                    Measures with Apple MagSafe 2 60watts:
                                    --------------------------------------------------------------------------------

                                    ----------------------
                                    PM_BATLOW_L
                                    ----------------------


                                    TP1 --> peak on 0.0875 then goes down to 0.035v (stable at 0.035v)

                                    R1410 pin 2 --> PM_BATLOW_L --> peak on 0.0875v then goes down to 0.035v (stable at 0.035v)
                                    R1410 pin 1 --> PP3V3_S5 --> 3.38v

                                    Q3000 pin 1 --> PP3V3_S4_TBT --> 0v
                                    Q3000 pin 2 --> TBT_BATLOW_L --> 0v
                                    Q3000 pin 3 --> PM_BATLOW_L --> peak on 0.0875v then goes down to 0.035v (stable at 0.035v)

                                    Comment


                                      #19
                                      Re: Macbook A1502 820-4924-A only smc bypass (Schematics measures and boardview inclu

                                      PM_BATLOW_L should go high if using a genuine Apple Magsafe2 60W. It needs to be a genuine Apple one, not a random eBay one, even with Apple logo, or a "refurbished" genuine one with a random cable, it needs to be Magsafe2 (not 1 even with 1 to 2 adapter), and it needs to be 60W or 85W. This board is very picky about it.
                                      OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                                      Comment

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