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820-01521 only shows 5V 0.04A

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    820-01521 only shows 5V 0.04A

    Hello,

    i've been working on macbook air 820-01521
    it is dead no charging. tried to connect to apple configurator always shows accessories not supported.

    using amp meter only shows 5V and 0.04A

    here are some measurements:

    PPBUS_G3H = 12.26V
    PP3V3_G3H = 3.275V
    PP5V_G3S = 0V
    PP20V_USBC_XA_VBUS = 5V (can i inject 20V 1A here?)

    #2
    Re: 820-01521 only shows 5V 0.04A

    First check why there is no 20v.
    Check CD chips.
    Most of the time if you manage to make them go board will wake up.

    Do not start from back

    PP5VG3S_EN present?

    How do you have 12.2v on main rail?
    Do you meassure with battery connected? (come on)
    Last edited by reassor; 04-20-2022, 03:15 AM.

    Comment


      #3
      Re: 820-01521 only shows 5V 0.04A

      PP20V_USBC_XA_VBUS = 5V (can i inject 20V 1A here?)
      No!! If you are not getting to 20v, something is wrong.

      Remove all power. Meter in diode mode.

      Red lead - yes RED meter lead to ground.

      Black meter lead to a LDO rail of each ACE power delivery controller.

      Check the LDO rails in diode mode of each ACE controller and post the readings.

      Repeat for each ACE device.

      Comment


        #4
        Re: 820-01521 only shows 5V 0.04A

        Originally posted by reassor View Post
        First check why there is no 20v.
        Check CD chips.
        Most of the time if you manage to make them go board will wake up.

        Do not start from back

        PP5VG3S_EN present?

        How do you have 12.2v on main rail?
        Do you meassure with battery connected? (come on)
        there is no rail called PP5VG3S_EN

        yes i have 12.26V on PPBUS rail

        Comment


          #5
          Re: 820-01521 only shows 5V 0.04A

          Originally posted by mon2 View Post
          No!! If you are not getting to 20v, something is wrong.

          Remove all power. Meter in diode mode.

          Red lead - yes RED meter lead to ground.

          Black meter lead to a LDO rail of each ACE power delivery controller.

          Check the LDO rails in diode mode of each ACE controller and post the readings.

          Repeat for each ACE device.
          PP3V3_UPC_XA_LDO = 26K ohm
          PP3V3_UPC_XB_LDO = 25K ohm
          PP5V_S5_LDO = 15.4K ohm
          Last edited by kingskie; 04-22-2022, 10:03 PM.

          Comment


            #6
            Re: 820-01521 only shows 5V 0.04A

            These are resistance readings. Do you have a diode scale on your meter? Can you post a pic of your meter?

            Then review my earlier post on how to use the diode mode scale and take the measurements.

            Comment


              #7
              Re: 820-01521 only shows 5V 0.04A

              Originally posted by mon2 View Post
              These are resistance readings. Do you have a diode scale on your meter? Can you post a pic of your meter?

              Then review my earlier post on how to use the diode mode scale and take the measurements.
              i'm using fluke 101
              Attached Files

              Comment


                #8
                Re: 820-01521 only shows 5V 0.04A

                Originally posted by kingskie View Post
                i'm using fluke 101
                Press the yellow button to cycle through to diode-mode.

                It'll likely show a diode symbol on the screen
                YouTube Repair Videos - https://www.youtube.com/user/19PLD73
                FlexBV BoardView software - Linux/OSX/Windows - http://pldaniels.com/flexbv

                Comment


                  #9
                  Re: 820-01521 only shows 5V 0.04A

                  As mon2 said kingskie, checking diode mode readings should start to give you a idea of which ACE controller may be acting differently. It may show all the same readings for all but it is a good place to start to see any differences.
                  Last edited by Simplebeans; 04-25-2022, 03:45 PM.

                  Comment


                    #10
                    Re: 820-01521 only shows 5V 0.04A

                    Originally posted by inflex View Post
                    Press the yellow button to cycle through to diode-mode.

                    It'll likely show a diode symbol on the screen
                    U3200
                    PP3V3_G3H_RTC = 0.425
                    PP3V3_UPC_XB_LDO = 0.466
                    PP1V8_UPC_LDOA = 0.482
                    UPC_XB_R_OSC = 0.481
                    UPC_XA_UART_TX = 0.682
                    PP1V1_UPC_XB_LDO_BMC = 0.460
                    UPC_XB_GPIO1 = 0.705
                    PP1V8_SLPS2R = 0.327
                    PP1V8_UPC_XB_LDOD = 0.444
                    UPC_XB_SPI_CS_L = 0.536
                    UPC_XB_SPI_CLK = 0.519
                    UPC_XB_SPI_MOSI = 0.541
                    UPC_XB_SPI_MISO = 0.537
                    I2C_UPC_XB_DBG_CTL_SCL = 0.716
                    I2C_UPC_XB_DBG_CTL_SDA = 0.715
                    PHV_INT_XB_G3H = 0.589
                    UPC_XB_GATE2 = 0.595
                    PPDCIN_G3H = 0.519
                    PP5V_G3S = 0.393
                    TBT_POC_RESET = 0.514
                    USB_X_RESET_L = 0.707
                    TBT_X_USB_PWR_EN = 0.492
                    PP20V_USBC_XB_VBUS = 0.108
                    USBC_XB_CC2 = 0.550
                    USBC_XB_CC2 = 0.533
                    USBC_XB_SBU2 = 0L
                    PD_TBT_XB_LSRX = 0.692
                    PD_TBT_XB_LSTX = 0.759
                    USB_UPOC_XB_F_P = 0.580

                    U3100
                    PP1V8_UPC_XA_LDOD = 0.448
                    PP1V1_UPC_XA_LDO_BMC = 0.461
                    PP3V3_UPC_XA_LDO = 0.468
                    PP1V8_UPC_XA_LDOA = 0.482

                    The lowest is PP20V_USBC_XB_VBUS and USBC_XB_SBU2 is 0L
                    Last edited by kingskie; 04-26-2022, 04:04 AM.

                    Comment


                      #11
                      Re: 820-01521 only shows 5V 0.04A

                      Do you see the same voltage and current draw for each USB type C port?

                      What are the voltage readings of the following?

                      PP1V8_SLPS2R

                      PP1V1_SLPS2R

                      Comment


                        #12
                        Re: 820-01521 only shows 5V 0.04A

                        Originally posted by mon2 View Post
                        do you see the same voltage and current draw for each usb type c port?

                        What are the voltage readings of the following?

                        pp1v8_slps2r

                        pp1v1_slps2r
                        pp1v8_slps2r = 1.793v
                        pp1v1_slps2r = 1.096v

                        Comment


                          #13
                          Re: 820-01521 only shows 5V 0.04A

                          These 2 rails are ok. They power the T2 device.

                          Do you see the same voltage and current draw for each USB type C port?

                          Comment


                            #14
                            Re: 820-01521 only shows 5V 0.04A

                            Originally posted by mon2 View Post
                            These 2 rails are ok. They power the T2 device.

                            Do you see the same voltage and current draw for each USB type C port?
                            yes they both have the same current draw...could it be T2 chip is the culprit or PMIC?

                            Comment


                              #15
                              Re: 820-01521 only shows 5V 0.04A

                              any suggestions?

                              Comment


                                #16
                                Re: 820-01521 only shows 5V 0.04A

                                SBC_XB_SBU2 = 0L

                                Is not correct for this diode reading. Can you check again?

                                It should be about 0.65.

                                Check also

                                USBC_XB_SBU1

                                USBC_XA_SBU1
                                USBC_XA_SBU2

                                Comment


                                  #17
                                  Re: 820-01521 only shows 5V 0.04A

                                  Originally posted by mon2 View Post
                                  SBC_XB_SBU2 = 0L

                                  Is not correct for this diode reading. Can you check again?

                                  It should be about 0.65.

                                  Check also

                                  USBC_XB_SBU1

                                  USBC_XA_SBU1
                                  USBC_XA_SBU2
                                  i checked USBC_XB_SBU2 from the test point that i attached still OL
                                  USBC_XB_SBU1 = OL
                                  USBC_XA_SBU1 = OL
                                  USBC_XA_SBU2 = OL
                                  Attached Files

                                  Comment


                                    #18
                                    Re: 820-01521 only shows 5V 0.04A

                                    Post a pic of your multimeter so we can confirm the diode mode setting.

                                    Comment


                                      #19
                                      Re: 820-01521 only shows 5V 0.04A

                                      Originally posted by mon2 View Post
                                      Post a pic of your multimeter so we can confirm the diode mode setting.
                                      this is my multimeter
                                      Attached Files

                                      Comment


                                        #20
                                        Re: 820-01521 only shows 5V 0.04A

                                        You are in ohms mode.

                                        Press the yellow button till you see the diode symbol and measure again.

                                        Comment

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