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    MacBook A1278 main 820-2530b not charge, it turns on only with battery

    hi, I have this macbook that works correctly with battery inserted, if I connect the power supply the light turns green but it does not charge, if I disconnect the battery and connect only the power supply the light turns green and the mac enters the ignition loop 4/5 sec, turns off and repeats itself,

    on the motherboard there are no traces of liquid or damaged components,

    I tested the 3.42 and they are constant both with power supply and with battery,
    advice on what signs I can start checking?
    the power supply indicator light never turns orange,
    power supply working on other macs
    thanks a lot
    Last edited by reset1986; 10-26-2021, 02:49 PM.

    #2
    Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

    hi.

    1) with the battery only - is the logic board able to report the battery status (value) ? If yes, then the SMBUS_I2C lines on the battery are working. Check for this.

    2) Try to do the PRAM reset to see if this fixes the issue.

    3) If the status of the battery is not being reported, then check & post the voltage readings on:

    a) SMBUS_BATT_SCL
    b) SMBUS_BATT_SDA

    4) Otherwise, study the power boot sequence showing on sheet # 3 / 81.

    The number inside each circle is the power on order that must be met to allow for the logic board to boot and operate normally.

    5) U7000 page should be studied which is the main charger and DC adapter power rail IC. It is possible that some component (mosfet?) is shorted. More on this after the above feedback is posted.
    Attached Files

    Comment


      #3
      Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

      Originally posted by mon2 View Post
      hi.

      1) with the battery only - is the logic board able to report the battery status (value) ? If yes, then the SMBUS_I2C lines on the battery are working. Check for this.

      2) Try to do the PRAM reset to see if this fixes the issue.

      3) If the status of the battery is not being reported, then check & post the voltage readings on:

      a) SMBUS_BATT_SCL
      b) SMBUS_BATT_SDA

      4) Otherwise, study the power boot sequence showing on sheet # 3 / 81.

      The number inside each circle is the power on order that must be met to allow for the logic board to boot and operate normally.

      5) U7000 page should be studied which is the main charger and DC adapter power rail IC. It is possible that some component (mosfet?) is shorted. More on this after the above feedback is posted.
      thanks, yes the battery percentage is managed and correct,
      Seeing the ignition sequence and with the battery inserted you go to bypass U7000,
      I check that air and post the results, thanks

      Comment


        #4
        Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

        Originally posted by mon2 View Post
        hi.

        1) with the battery only - is the logic board able to report the battery status (value) ? If yes, then the SMBUS_I2C lines on the battery are working. Check for this.

        2) Try to do the PRAM reset to see if this fixes the issue.

        3) If the status of the battery is not being reported, then check & post the voltage readings on:

        a) SMBUS_BATT_SCL
        b) SMBUS_BATT_SDA

        4) Otherwise, study the power boot sequence showing on sheet # 3 / 81.

        The number inside each circle is the power on order that must be met to allow for the logic board to boot and operate normally.

        5) U7000 page should be studied which is the main charger and DC adapter power rail IC. It is possible that some component (mosfet?) is shorted. More on this after the above feedback is posted.
        hi, I found Q7030 pin 123 CHGR_PHASE and pin 4 CHGR_UGATE measured in diode mode low value 10ohm

        q7030 tested looks ok, replaced U7000 ISL6258a,
        the value is back to high, given power to the motherboard with power supply, switching on and off in repetition,
        measured again CHGR_PHASE and CHGR_UGATE again low value 10/12 ohm,
        there are no short

        do you have any advice? thanks a lot
        Last edited by reset1986; 10-26-2021, 07:00 PM.

        Comment


          #5
          Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

          Review this webpage:

          https://www.badcaps.net/forum/showthread.php?t=90356

          Post the voltages on each pin of U7000 with the adapter and battery connected.

          Post voltages of U7000 without adapter but battery connected.

          Comment


            #6
            Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

            Originally posted by mon2 View Post
            Review this webpage:

            https://www.badcaps.net/forum/showthread.php?t=90356

            Post the voltages on each pin of U7000 with the adapter and battery connected.

            Post voltages of U7000 without adapter but battery connected.
            ok just measured

            with battery inserted and mac turned off
            1 0V
            2 0V
            3 0V
            4 3.44V
            5 0V
            6 3.44
            7 0
            8 0
            9 0
            10 3.42
            11 3.42
            12 3.44
            13 3.42
            14 0
            15 0.05
            16 3.75
            17 10.66
            18 10.66
            19 0
            20 0
            21 0
            22 GND
            23 10.66
            24 10.66
            25 10.34
            26 14
            27 13.90
            28 13.80
            29 GND

            with battery inserted and power supply, mac off with green led
            1 0V
            2 16.45
            3 3.92
            4 3.44V
            5 0.18
            6 3.44
            7 0.72
            8 1.76
            9 0.03
            10 3.42
            11 3.42
            12 3.44
            13 3.42
            14 3.30
            15 0.05
            16 3.22
            17 10.65
            18 10.65
            19 5.06
            20 5.06
            21 0
            22 GND
            23 10.66
            24 10.58
            25 10.13
            26 16.05
            27 16.30
            28 16.30
            29 GND

            thanks

            Comment


              #7
              Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

              1) What is the voltage of PPBUS_G3H with the adapter & battery ?

              2) What is the voltage of PPBUS_G3H with the adapter (only) & no battery ?

              3) Power down, remove adapter & battery.

              Meter in resistance mode.

              Post the resistance for the following:

              a) source (1-2-3) & drain (5-6-7-8) of Q7050

              b) source (1-2-3) & gate (4) of Q7050

              c) gate (4) & drain (5-6-7-8) of Q7050

              4) Are you using an original magsafe 85W power supply ? With the battery out, does the magsafe LED turn orange (amber) ?

              5) Can you test with another known good battery ?

              6) Place meter in diode mode and post the diode readings for the SCL / SDA lines for the battery interface.

              a) Red meter lead to ground. Black meter lead on SMBUS_BATT_SCL. Diode reading ?

              b) Red meter lead to ground. Black meter lead on SMBUS_BATT_SDA. Diode reading ?
              Last edited by mon2; 10-27-2021, 05:15 AM.

              Comment


                #8
                Re: MacBook A1278 main 820-2936b not charge, it turns on only with battery

                Originally posted by mon2 View Post
                1) What is the voltage of PPBUS_G3H with the adapter & battery ?

                2) What is the voltage of PPBUS_G3H with the adapter (only) & no battery ?

                3) Power down, remove adapter & battery.

                Meter in resistance mode.

                Post the resistance for the following:

                a) source (1-2-3) & drain (5-6-7-8) of Q7050

                b) source (1-2-3) & gate (4) of Q7050

                c) gate (4) & drain (5-6-7-8) of Q7050

                4) Are you using an original magsafe 85W power supply ? With the battery out, does the magsafe LED turn orange (amber) ?

                5) Can you test with another known good battery ?

                6) Place meter in diode mode and post the diode readings for the SCL / SDA lines for the battery interface.

                a) Red meter lead to ground. Black meter lead on SMBUS_BATT_SCL. Diode reading ?

                b) Red meter lead to ground. Black meter lead on SMBUS_BATT_SDA. Diode reading ?

                PPBUS_G3H with power supply and battery 10.60

                PPBUS_G3H with power supply and without battery, goes into power on off, I measure 12.50V, then turns off I measure 3.5V
                PPBUS_G3H measured on F7040


                q7050 should be the q7055 on this main 820-2936b, my mistake, I correct the title , place schematic and brd
                q7055 measurements
                a) 123--5678 113Kohm, inverting the wires to infinity
                b) 123--4 1.4 Mohm by inverting the leads infinity
                c) 4 --- 5678 I have no 2K-200K-2M scale readings

                original power supply working on another 1278, new battery charged to 40%

                SMBUS_SMC_BSA_SCL and SMBUS_SMC_BSA_SDA
                measured in diode mode, 223 both

                thanks for your help
                Attached Files

                Comment


                  #9
                  Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                  1) What chip was soldered in @ U7000 ? It has to be the ISL6259.

                  2) Desolder D6950 and remove all power (no adapter / no battery) and check the diode readings again on the battery SMBUS_SMC_BSA_SCL and SMBUS_SMC_BSA_SDA lines.

                  Post the results.

                  Comment


                    #10
                    Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                    L2008-M2009 MacBooks use ISL6258 not ISL6259.
                    OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                    Comment


                      #11
                      Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                      L2008-M2009 MacBooks use ISL6258 not ISL6259.
                      OMG. The 820-2530 uses ISL6258 @ U7000 ?

                      The 820-2530 schematic shows as ISL6259.

                      Noting this correction, to the OP, which part do you have @ U7000 ?

                      Comment


                        #12
                        Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                        Originally posted by piernov View Post
                        L2008-M2009 MacBooks use ISL6258 not ISL6259.
                        Originally posted by mon2 View Post
                        OMG. The 820-2530 uses ISL6258 @ U7000 ?

                        The 820-2530 schematic shows as ISL6259.

                        Noting this correction, to the OP, which part do you have @ U7000 ?
                        here I am, U7000 isl6259A,
                        I made a mistake in the title
                        the motherboard is 820-2936b, I posted the schematic, soon I will post measurements of SMBUS_SMC_BSA_SCL and SMBUS_SMC_BSA_SDA lines. without diode

                        thanks a lot

                        Comment


                          #13
                          Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                          Ok. 820-2936b from schematics and Louis' forum notes U7000 as ISL6259. Be sure that it is soldered properly - 'make it dance' with the flux and hot air.

                          Comment


                            #14
                            Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                            Originally posted by mon2 View Post
                            Ok. 820-2936b from schematics and Louis' forum notes U7000 as ISL6259. Be sure that it is soldered properly - 'make it dance' with the flux and hot air.
                            desoldered D6950
                            SMBUS_SMC_BSA_SCL and SMBUS_SMC_BSA_SDA 223 measured in diode mode, 223 both as when d6950 is soldered

                            but the q7030 123--4 10 Ohm is normal?

                            isl6259 welded correctly

                            thanks

                            Comment


                              #15
                              Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                              but the q7030 123--4 10 Ohm is normal?
                              Sounds low to me. Desolder it and check the resistance again on this mosfet when it is out of circuit.

                              Source - drain ?

                              Source - gate ?

                              gate - drain ?

                              Likely it needs to be replaced.

                              The diode values may be ok on the I2C lines but internet (Louis' forum) - states it should be about 0.4 - 0.45. For now, do not worry about these values.

                              The mosfet @ Q7030 is of concern.

                              See the tables here for guidance.

                              http://electronicsbeliever.com/how-t...-is-defective/

                              Comment


                                #16
                                Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                                Originally posted by mon2 View Post
                                Sounds low to me. Desolder it and check the resistance again on this mosfet when it is out of circuit.

                                Source - drain ?

                                Source - gate ?

                                gate - drain ?

                                Likely it needs to be replaced.

                                The diode values may be ok on the I2C lines but internet (Louis' forum) - states it should be about 0.4 - 0.45. For now, do not worry about these values.

                                The mosfet @ Q7030 is of concern.

                                See the tables here for guidance.

                                http://electronicsbeliever.com/how-t...-is-defective/
                                ok, unsoldered q7030, q7035, q7055

                                test with 200K scale
                                q7030, q7035 q7055
                                123 --- 5678 110K
                                tapping pin 4
                                123 --- 5678 76K

                                123 --- 4 0 Kohm
                                4 ---- 5678 0 Kohm

                                inverting the tips I have no measures, they seem ok

                                q7030 on the motherboard I still have 10 ohms between 123--4
                                desoldering U7000 the value increases,
                                i had tried to replace U7000 the value before power on was correct between 123--4 of q7030, then it decreased again

                                Comment


                                  #17
                                  Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                                  Hi! I have the same exact problem than you!
                                  Low resistance between Ugate and phase of U7000. (Like 4 to 10 ohms)
                                  Also "Looping" every 5 seconds in PPBUS_G3H with charger only.

                                  With battery works fine. Already replaced Q7030 and U7000 with brand new chips. Same problem

                                  This is PPBUS_G3H readings.
                                  I'm suspecting SMC but I want to discard everything before changing it.
                                  Attached Files

                                  Comment


                                    #18
                                    Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                                    Ok, I think I'm getting closer.

                                    Please, take a reading at U7000 pin 26.

                                    Mine is around 18v. It should be 0 so Q7080 saturates through the voltage divider.

                                    I have changed U7000 several times. My thoughts are that the SMC isn't communicating to ISL through SMBUS_SMC_BSA_SCL & SMBUS_SMC_BSA_SDA correctly.

                                    I'll try and check the comunication.

                                    Comment


                                      #19
                                      Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                                      U7000 is a delicate device. If you have not done so already, use lots of flux and dial up high heat with good air pressure.

                                      For our tool, 500C and 50-65 percent on the air around the ic. Then we wait till the chip dances around the pcb pads where it lives. Just be careful to not disturb nearby parts. Then we are confident the balls have aligned ok.

                                      Just did the same recently for an ipad TriStar repair.

                                      Comment


                                        #20
                                        Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

                                        Thanks mon2 I'll try it again. Maybe is wrongly soldered.
                                        @reset86, any news?

                                        Comment

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