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Macbook A1990 820-01041-A Dark Display

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    Macbook A1990 820-01041-A Dark Display

    Hello, I have a MacBook Pro 15 inch 2018. A1990 Board 820-01041-A. The MacBook has water damage. It works but the display stays black. I took a picture of the LVDS connector. there you can see on the thick pin over IPX that there was a short circuit. there is also zero volts. Have any of you had the same problem? Thanks
    Attached Files

    #2
    Re: Macbook A1990 820-01041-A Dark Display

    Hello, I have now made a few more measurements on the board with the power supply connected.

    Comment


      #3
      Re: Macbook A1990 820-01041-A Dark Display

      Originally posted by Strolch View Post
      Hello, I have now made a few more measurements on the board with the power supply connected.
      LCD pin top right 0.0072V
      bottom right 3.369V
      top left and bottom left 5.11V
      Attached Files

      Comment


        #4
        Re: Macbook A1990 820-01041-A Dark Display

        on the second picture I measured 0.004V for the 5 in the row and 0.0035V for picture 3 and 12.55V for the fuse

        Comment


          #5
          Re: Macbook A1990 820-01041-A Dark Display

          Hi. Best to use pin numbers from the BV file for this logic board.

          Can you measure and post your voltage readings of J8500?

          In the meantime, need to collect the 10,000 leaves in the backyard - it is a favorite past time. Want to burn them along with the audio equipment used by the neighbors for their outdoor karoake sessions.
          Attached Files

          Comment


            #6
            Re: Macbook A1990 820-01041-A Dark Display

            Ok, pin 1to pin 46 or which pins should I measure? greeting

            Comment


              #7
              Re: Macbook A1990 820-01041-A Dark Display

              Start with the voltage to ground check of each of the I2C pins.

              See attached.
              Attached Files

              Comment


                #8
                Re: Macbook A1990 820-01041-A Dark Display

                Hi,
                i have
                Pin 24=5.108V
                Pin 26=5.104V
                Pin 28=3.36V
                Pin 30=3.36V
                Pin 32=0.0004V
                Pin 34-40 All= 1.7934V

                Comment


                  #9
                  Re: Macbook A1990 820-01041-A Dark Display

                  Voltage on pin #45 ?

                  Voltage on pin #46 ?

                  Comment


                    #10
                    Re: Macbook A1990 820-01041-A Dark Display

                    Pin 45 and Pin 46= 5.110V

                    Comment


                      #11
                      Re: Macbook A1990 820-01041-A Dark Display

                      Maybe U5210?

                      Comment


                        #12
                        Re: Macbook A1990 820-01041-A Dark Display

                        Fault may be that U9850 is damaged (MUX).

                        See 'NO IMAGE' here:

                        https://repair.wiki/w/A1990_2018-201...ar_MacBook_Pro

                        If you suspect U5210 - measure the voltage of the I2C lines on both sides of U5210.

                        That is,

                        I2C_DISP_SCL
                        I2C_DISP_SDA

                        I2C_TCON_SCL
                        I2C_TCON_SDA

                        Comment


                          #13
                          Re: Macbook A1990 820-01041-A Dark Display

                          Hi,
                          The link doesn't work.
                          https://repair.wiki/w/A1990_2018-201...ar_MacBook_Pro

                          Comment


                            #14
                            Re: Macbook A1990 820-01041-A Dark Display

                            But I have already exchanged the chip on an A1707 and then it was fine again! I will try it. br

                            Comment


                              #15
                              Re: Macbook A1990 820-01041-A Dark Display

                              Hi mon2,

                              I swapped the U9850. The display is getting power now but I don't have a backlight. greeting

                              Comment


                                #16
                                Re: Macbook A1990 820-01041-A Dark Display

                                I will look at the Backlight Flex Cable Connector of the A1989 A1990 A1706

                                Comment


                                  #17
                                  Re: Macbook A1990 820-01041-A Dark Display

                                  Very good - do check the backlight voltage at the logic board to see if it is being created.

                                  Comment


                                    #18
                                    Re: Macbook A1990 820-01041-A Dark Display

                                    J8500 Pin 43?

                                    Comment


                                      #19
                                      Re: Macbook A1990 820-01041-A Dark Display

                                      I have from 8470-C8473=. 0,005V

                                      Comment


                                        #20
                                        Re: Macbook A1990 820-01041-A Dark Display

                                        Measure the voltage to ground for the following points of interest:

                                        EDP_BKLT_EN

                                        PPVIN_S0SW_LCDBKLT_R

                                        LCDBKLT_EN_L

                                        PPVIN_S0SW_LCDBKLT
                                        Attached Files

                                        Comment

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