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MacBook Pro 15" 2017 A1707 Touchbar No power

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    #81
    Re: MacBook Pro 15" 2017 A1707 Touchbar No power

    Confirm the diode readings of both U300 & u400.

    Measure the diode readings of the other CD3215 devices on the board and compare if their readings are similar and in this range.

    Post the values.

    Was U300 more warm to touch than usual ?

    Comment


      #82
      Re: MacBook Pro 15" 2017 A1707 Touchbar No power

      hi, thanks for the quick response.

      The readings for LDOs are:
      u3100 :
      pp1v8_upc_xa_ldod : 0.466
      pp3v3_upc_xa_ldo : 0.480
      pp1v1_upc_xa_ldo_bmc : 0.486
      pp1v8_upc_xa_ldoa : 0.503

      u3200
      pp1v8_upc_xb_ldod : 0.458
      pp3v3_upc_xb_ldo : 0.479
      pp1v1_upc_xb_ldo_bmc : 0.477
      pp1v8_upc_xb_ldoa : 0.496

      ub300:
      pp1v8_upc_ta_ldod : 0.450
      pp3v3_upc_ta_ldo : 0.478
      pp1v1_upc_ta_ldo_bmc : 0.474
      pp1v8_upc_ta_ldoa : 0.490

      ub400:
      pp1v8_upc_tb_ldod : 0.458
      pp3v3_upc_tb_ldo : 0.484
      pp1v1_upc_tb_ldo_bmc : 0.474
      pp1v8_upc_tb_ldoa : 0.492

      so those look all good?

      I never touched the chips before, but got as warm as close to burning my finger, does not feel good.

      Comment


        #83
        Re: MacBook Pro 15" 2017 A1707 Touchbar No power

        Agreed. Sounds too hot.

        Perhaps consider to reflow the hot CD3215 ? Maybe it is damaged but try the reflow again.

        Comment


          #84
          Re: MacBook Pro 15" 2017 A1707 Touchbar No power

          Originally posted by mon2 View Post
          Agreed. Sounds too hot.

          Perhaps consider to reflow the hot CD3215 ? Maybe it is damaged but try the reflow again.
          hi,

          Reflowed UB300.
          UB300 is now reading 130 mA about.

          UB400 has good readings on LDOs and no shorts but does not power on.
          Perhaps it's poorly connected on the power lines or broken.
          I tried to reflow it, no change.

          the ports on the other side work too somehow, 130 mA about.

          I suppose UB400 needs to come off again, but given that I have no reballed spare or reball solder, I have to leave it for now.

          Unfortunately I do not have time for a while to pursue this, I will probably order some reball solder or more chips, depending on if I find another broken one.
          Lack of time sucks, might keep it for spared for a while.

          It has been a great learning experience and I hope to get back to it.
          @powerblackout would you mind uploading the TBT rom incase me or anyone else needs it?

          Thanks a lot!

          Comment


            #85
            Re: MacBook Pro 15" 2017 A1707 Touchbar No power

            Originally posted by Stephen View Post
            Also our board is
            820-00281-A

            Hi everybody, I have a A1707 MacBook 2016 that turns on then powers off after few minutes. It cannot turn on when I use the PSU only with the type-c charger or battery. Now there's no os on it. SSD does not show when booting from drive on startup however it does show in disk utility. It powers off after about 1-2 minutes into installing OS from storage drive.

            PPBUS 13V

            Comment


              #86
              Re: MacBook Pro 15" 2017 A1707 Touchbar No power

              What is the 820-xxxx board number on your A1707 logic board ?

              1) Does your power adapter go to 20V to power your logic board ? Do you have a USB C meter ?

              2) See attached. Measure the voltage of PPBUS_G3H at the referenced fuses.
              Attached Files
              Last edited by mon2; 08-05-2022, 03:29 PM.

              Comment


                #87
                Re: MacBook Pro 15" 2017 A1707 Touchbar No power

                Hi Mon2, finally you are up to help me as well ?

                Appreciate you I hope we can start working on this now. Board is 820-00281-A, 2016.

                1) It shows 19.3V, 0.9399 amps then kind of goes back to 0 amps after it cycles(0.9399 - 0.000) about twice then stays on 19.6V 0.00 for the board only when battery and bmu cable is connected to the board; it starts at 19.6V 0.00 then I see 11V / 13V at 0.00 then 4.99V the cycles between 340ma, 370ma, 24ma, 27ma, 24ma 0.00ma.

                I also saw that when BMU cable is connected to the board(without battery) it reads 19.6V 1.1amps then stays at 19.6V 0.00. PPBUS is 12.6 either way

                Comment


                  #88
                  Re: MacBook Pro 15" 2017 A1707 Touchbar No power

                  The battery BMU communication is over the I2C / SMBUS interface. Locate the battery connector and in the schematic will be a dual ESD diode component.

                  Often it is D6950 but do confirm the reference in the schematic. I do not have the schematic in front of me at this time.

                  Once you find this part, measure the voltage on the SCL pin to ground. Meter in 5 volts dc or higher.

                  Repeat to measure the SDA voltage to ground. Post each measurement.

                  Next, remove all power. Meter in resistance mode.

                  Check the resistance to ground of these same pins.

                  We are checking to see if this dual esd diode is defective which will halt the proper operation of these common communication lines.
                  Last edited by mon2; 08-06-2022, 04:45 AM.

                  Comment


                    #89
                    Re: MacBook Pro 15" 2017 A1707 Touchbar No power

                    See attached.

                    1) Is the battery a known good battery ?

                    2) what is the present voltage on the battery ?

                    3) Measure this voltage @ PPVBAT_G3H_CONN and post the voltage value. This is the voltage that is being used to interface with the logic board via the battery mosfet @ Q7065.

                    4) Leave the power adapter OFF. Using only the battery, what voltage do you see @ Q7065, pin # 1-2-3 (SOURCE; PPVBAT_G3H_CHGR_R) ?

                    5) With care, take the measurements of the following pins:

                    TBA_CSO_N
                    TBA_CSO_P


                    This is the current feedback loop used by U7000. The ISL9239 IC takes as input the voltage on each of the above legs and monitors the voltage drop across the current sense resistor @ R7060.

                    Based on the voltage drop, U7000 is able to determine if there is too much of a load on the logic board and will shut down the use of the battery mosfet and/or charging.

                    So it is important that the resistor values remain as per the original PCB assembly schematic. Respectively, the feedback voltage must reach the ISL9239 otherwise it assumes that the voltage drop is caused by a dangerous and excessive load and is beyond the expected current draw -> shut it down mode.

                    6) Will be a good idea to check if the battery mosfet (Q7065) is ok with a resistance check.

                    Remove all power / remove the battery. Meter in resistance mode.

                    Measure the resistance of Q7065 as follows:

                    Source (1-2-3) & drain (5-6-7-8)
                    Source (1-2-3) & gate (4)
                    Gate (4) & drain (5-6-7-8)


                    Post each measurement and the meter scale used. If your meter shows '1' or 'OL' then the meter scale is too low -> switch to a higher scale till the meter is able to measure the resistance values. Too low of a reading means this mosfet is leaking / defective and must be replaced.
                    Attached Files

                    Comment


                      #90
                      Re: MacBook Pro 15" 2017 A1707 Touchbar No power

                      Hi Brother,

                      Thank you for getting back with your reply. I have located the D6950


                      PIN 1 - SMBUS_SMC_5_G3_SDA = 3.398 - 3.401 ,
                      PIN 2 - SMBUS_SMC_5_G3_SCL = 3.398 - 3.401

                      The reading isn't stable for both pins, started reading from 3.0 M ohms and declined till it stopped at 130.2K

                      Comment


                        #91
                        Re: MacBook Pro 15" 2017 A1707 Touchbar No power

                        Voltage and resistance are fine. So the ESD device is not impacting the communication lines.

                        1) Are you using the official power adapter or one that is capable of powering this logic board ? Suggest 60W or higher power supply.

                        2) After the board powers off -> check the voltages of PPBUS_G3H.

                        3) What is the history of this unit ? Just died one day or for some other reason ? Do search for clues on the logic board.

                        Continue to review the other suggestions above while I take care of my weeds...err lawn.

                        Comment


                          #92
                          Re: MacBook Pro 15" 2017 A1707 Touchbar No power

                          1) No, do not have any other device to test it.

                          2) 2.195 V on the battery. connect the com to - and the Red probe to + on the battery board

                          3) PPVBAT_G3H_CONN is 12.66 V

                          4) @ Q7065, pin # 1-2-3 (SOURCE; PPVBAT_G3H_CHGR_R) = 12.66v

                          5) TBA_CSO_N = 12.66v
                          TBA_CSO_P = 12.66v

                          6) Q7065 , shows 10 M ohms rose up to 50 MB ohms then 0L for all 8 pins. all measure in diode mode and the mosfet seems fine.

                          Comment


                            #93
                            Re: MacBook Pro 15" 2017 A1707 Touchbar No power

                            Originally posted by mon2 View Post
                            Voltage and resistance are fine. So the ESD device is not impacting the communication lines.

                            1) Are you using the official power adapter or one that is capable of powering this logic board ? Suggest 60W or higher power supply.

                            2) After the board powers off -> check the voltages of PPBUS_G3H.

                            3) What is the history of this unit ? Just died one day or for some other reason ? Do search for clues on the logic board.

                            Continue to review the other suggestions above while I take care of my weeds...err lawn.
                            1)official 60W

                            2) stays at 12.6

                            3) Customer was selling it off so had to wipe it out before final sale, then now powers on alright but do not stay on for more than 1 minute.

                            Comment


                              #94
                              Re: MacBook Pro 15" 2017 A1707 Touchbar No power

                              Hi, I am back to let you know I tried so many ways to find a problem on the board and guess the technique I used ?

                              1) With all power removed the coils do not have a short; but when an adaptor is plugged in, I see the PP5V_S4 (L7600) is shorted (20 ohms) and cannot turn on to 5V just zero,

                              2) With all power removed, I injected 5V onto that rail and I saw U7800 lighting up to about 38 degrees celsius with 0.03Amps.

                              3) I pull the PMIC out and the rail is not shorted again (I injected 5V again then 0 amps draw). I guess now I will have to replace the PMIC. I did replace U7650 and didn't solve the issue. Please post your replies so I can know the way forward. I heard shoutouts from KamiL to Piernov on this same issue later when I looked up for this issue from YT.

                              Comment

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