A2159 Touch bar No backlight

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  • m_12adel
    Member
    • Dec 2009
    • 12
    #1

    A2159 Touch bar No backlight

    I have MacBook Pro A2159 EMC 3301 board 820-01598 that Touch bar is working but with No Backlight, I replaced it with a new one , have the same issue
    Checked both connecters J5110 , J5100 from board side and from Touchbar side , it have no issue
    so if anyone know how to make sure backlight voltage is exist , and which pin?
    Tags: None
    • mon2
      Badcaps Legend
      • Dec 2019
      • 13887
      • Canada
      #2
      Re: A2159 Touch bar No backlight

      From a review of the signal names, this is a single lane MIPI DSI design.

      So you have your

      MIPI DATA_P/DATA_N lanes - the pair = single lane design
      MIPI CLK_P/CLK_N lanes - always required on every MIPI design

      The above are used to configure and stream out the display data.

      Since you can see the display data - the above MIPI lines are ok.

      Backlight will be a power rail also present on the same connector.

      Check PP3V3_G3HSW_DFR on J5110 and post the voltage measurement. This voltage rail is passing through a load switch @ U5111. This load switch is enabled through pin # 1.

      Do also check if the load switch is being enabled or not.

        Comment

        • m_12adel
          Member
          • Dec 2009
          • 12
          #3
          Re: A2159 Touch bar No backlight

          PP3V3_G3HSW_DFR on J5110 pin 18,20,22 is 3.3V
          I couldn't check Voltage on U5111 but R5110 is 7.5kΩ

          side question: can I power on board outside frame without power button?

            Comment

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