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Macbook Air A1466 Dead

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    #1

    Macbook Air A1466 Dead

    Logic board:820-00165A

    History: No liquid spill or corrosion. Has come after repair attempt by others. Customer says there was charging issue but the unit was working well but i've received it as dead unit.

    MAgsafe light glows green and then orange , No fan spin. consumption on DC supply 0.0027A.

    PPBUS_G3H_R-1.16V(measured at D7005)
    ISL6259 measurements:

    PIN1-0V
    PIN2-15.8V
    PIN3-4.12V
    PIN10-3.3V
    PIN11-3.3V
    PIN12-3.42V
    PIN17-18: 1.12V
    PIN27-28:1.12V

    Resistance between pin17-18 -3.5 Ohms
    Resistance between pin27-28:21 Ohms

    Charger IC seems to be replaced by earlier technician-so i replaced it with a new IC to be sure. All the measurements are with new charging IC. Charging IC is soldered properly(checked under microscope).

    Can this unit be revived?? Please suggest the way forward.

    PS: I've checked resistor R7110/7111/7185/7186 out of circuit and they all measure as per schematic.
    Last edited by mcplslg123; 11-27-2021, 06:10 AM.
    Tags: None
    #2
    Re: Macbook Air A1466 Dead

    PPBUS_G3H_R-1.16V(measured at D7005)
    So PPBUS_G3H rail is not correct.

    1) Voltage of PPBUS_G3H @ R7006, pin # 1 ?

    2) Voltage of PPBUS_G3H @ F7140, pin # 1 ? F7140, pin # 2 ?

    3) Voltage of PPDCIN_G3H ?

    Also check and post:

    4) PPDCIN_G3H_CHGR voltage

    5) CHGR_UGATE (pin 24) U7100

    6) CHGR_LGATE (pin 21) U7100

    Next, remove all power. Meter in resistance mode.

    Resistance to ground on F7140, pin #2 ?

    If F7140 is not blown, remove it and check resistance to ground again of F7140, pin #2.

    With F7140 removed, what is the voltage @ F7140 PCB pad, pin # 1 ?
    Last edited by mon2; 11-27-2021, 06:47 AM.

    Comment

      #3
      Re: Macbook Air A1466 Dead

      1) Voltage of PPBUS_G3H @ R7006, pin # 1 ? 1.12V

      2) Voltage of PPBUS_G3H @ F7140, pin # 1 ? 1.12V F7140, pin # 2 ? 1.12V

      3) Voltage of PPDCIN_G3H ? 16.4V

      Also check and post:

      4) PPDCIN_G3H_CHGR voltage 1.14V

      5) CHGR_UGATE (pin 24) U7100 5.0V

      6) CHGR_LGATE (pin 21) U7100 -0.04V

      Next, remove all power. Meter in resistance mode.

      Resistance to ground on F7140, pin #2 ? 9KOHMS

      If F7140 is not blown, remove it and check resistance to ground again of F7140, pin #2.

      With F7140 removed, what is the voltage @ F7140 PCB pad, pin # 1 ?

      Comment

        #4
        Re: Macbook Air A1466 Dead

        @mon2, I forgot to tell that i already tried removing F7140 and measuring voltage on both pads. The voltage of PPBUS_G3H remains same even after removing F7140. So the problem is perhaps not in load side but source side. Btw, F7140 is not blown

        Comment

          #5
          Re: Macbook Air A1466 Dead

          See here:

          https://youtu.be/dX4nahRELzs

          Comment

            #6
            Re: Macbook Air A1466 Dead

            @mon2, i watched that video but the symptoms are note same. However, i've solved the case. I measured resistance on top of Q7180 and it was comparable to good board, so i injected 15V from my dc supply on top of Q7180(pin1) and it chimed with display. So i did a hack to solve it. I jumpered a wire from J7000(Pin1-2) to Q7180(pin1). Everything is working perfectly and battery is also charging fine.

            I know not the perfect way to solve but i tried my level best and could'nt find any fault and so just hacked it.

            Thanks to all who responded.

            Comment

              #7
              Re: Macbook Air A1466 Dead

              I am thinking that the PCB trace for PPDCIN_G3H to Q7180, pin # 1-2 was blown.

              Good that you have it working.

              Comment

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