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MacBook 12" A1534, 820-00687-B no image HELP

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    #1

    MacBook 12" A1534, 820-00687-B no image HELP

    MacBook 12 arrived. does not turn on. no voltage PP5V_S4 =0

    PPBUS_G3H=8.7v
    PPVIN_G3H_P3V3G3H=19.9v
    PPBUS_S5_HS_COMPUTING_ISNS=8.7v
    PPVBUS_LIO=19.9v
    PPDCIN_G3H=19.9v
    PP3V3_G3H=3.3v
    PP3V3R3V0_AON=3.3v
    PPVRTC_G3H=3v
    PP5V_G3H=5v
    PP5V_S5=5v
    PP5V_S4= 0V
    PP5V_S0=0V
    PP3V3_S5=3.3V
    PP3V3_SUS=3.3V
    PP3V3_S4 = 0.013V
    PP3V3_S0 = 0.077V
    TELL ME WHAT ELSE TO CHECK OR DO YOU HAVE ANY THOUGHTS WHAT MAY BE?
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    #2
    Remove all power. Meter in resistance mode. Measure the resistance to ground of each and every rail that is not of the correct value. Post each measurement. If the resistance is too low, the excessive current draw will be sensed by the current sense circuits and then force a power off.

    Comment

    • PITERPENY
      #2.1
      PITERPENY commented
      12-22-2023, 11:07 AM
      Editing a comment
      HI LEGEND MON2
    #3
    Originally posted by mon2 View Post
    Remove all power. Meter in resistance mode. Measure the resistance to ground of each and every rail that is not of the correct value. Post each measurement. If the resistance is too low, the excessive current draw will be sensed by the current sense circuits and then force a power off.
    PP5V_S4= 0.217V
    PP5V_S0=0.450V
    PP3V3_S4 = 0.437V
    PP3V3_S0 = 0.314V

    Comment

      #4
      Hi. These are maybe diode mode readings? Remove all power. Meter in resistance mode. One meter probe (color does not matter for resistance checks) on the point to test. Other meter probe to ground. We are interested in the resistance measurement and the units of measurement. For example, ohms / kohms, etc. Post each measurement. We are checking if you have a low resistance on the rail which means a shorted component.

      If the above are diode mode readings then most likely there are no shorts on the power rails you have measured.

      Comment

        #5
        Originally posted by mon2 View Post
        Hi. These are maybe diode mode readings? Remove all power. Meter in resistance mode. One meter probe (color does not matter for resistance checks) on the point to test. Other meter probe to ground. We are interested in the resistance measurement and the units of measurement. For example, ohms / kohms, etc. Post each measurement. We are checking if you have a low resistance on the rail which means a shorted component.

        If the above are diode mode readings then most likely there are no shorts on the power rails you have measured.
        The above measurements were carried out in red-to-ground diode mode.
        below black to ground in resistance mode:
        PPBUS_G3H=6.85 kOhm
        PPVIN_G3H_P3V3G3H=11kOhm
        PPBUS_S5_HS_COMPUTING_ISNS=6.85kOhm
        PPVBUS_LIO=0.66 kOhm
        PPDCIN_G3H=13.8kOhm
        PP3V3_G3H=6.04kOhm
        PP3V3R3V0_AON=14.2kohm
        PPVRTC_G3H=8.73kohm
        PP5V_G3H=8.78kohm
        PP5V_S5=8.43kohm
        PP5V_S4= 1.52kohm
        PP5V_S0=10.3kohm
        PP3V3_S5=5.83kohm
        PP3V3_SUS=3 ohm
        PP3V3_S4 = 7.92kohm
        PP3V3_S0 = 1.68 kohm
        🧐

        Comment

          #6
          on S5 the indicators are all normal, but on the next stage S4 there is nothing

          Comment

            #7
            Are these indicators normal?

            PPVCORE_S0_CPU=14.8 ohm (0v)
            PPVCORE_S0_GT=12.7 ohm (0v)
            PPVCORE_SUS_PCH=1.2 ohm (0v)

            Comment

              #8
              anyone? advise something or tell me something....

              Comment

                #9
                What is the voltage to ground of All_SYS_PWRGD?

                is it stable or pulsing?

                Comment

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