lenovo x240 Screen Backlight not present

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  • salamonnorbert
    New Member
    • Feb 2021
    • 3
    • Romania
    #1

    lenovo x240 Screen Backlight not present

    Hello people of Badcaps!

    Facing a problem since weeks and I got no idea how to fix this one.

    Laptop: lenovo x240 with NM-A091 motherboard

    We tested the screen baklight and all works. Ribbon cable is good it is clearly some sort of motherboard issue.

    I do not want to fix the board if an alternative solution is possible with a bridge on the screen. (Seen some videos of people bridging LED_PWM and LED_IN) but I don't know how to do that with this particular panel.

    Any advice? Thanks in advance

    P.s: there is a weird mark on the old screen connector. Can it be related?
    Attached Files
    Last edited by SMDFlea; 04-15-2021, 01:57 AM.
    Tags: None
    • mcplslg123
      Badcaps Legend
      • Jun 2015
      • 7262
      • india
      #2
      Re: Screen Backlight not present

      Measure voltage and resistance on pin 12/13/23/24/26 of LCD Connector. Be careful while measuring.

        Comment

        • salamonnorbert
          New Member
          • Feb 2021
          • 3
          • Romania
          #3
          Re: Screen Backlight not present

          Originally posted by mcplslg123
          Measure voltage and resistance on pin 12/13/23/24/26 of LCD Connector. Be careful while measuring.
          Thanks a lot for replying!

          0v at every pin wich you suggested. The multimeter is not faulty. What do you suggest?

            Comment

            • mcplslg123
              Badcaps Legend
              • Jun 2015
              • 7262
              • india
              #4
              Re: lenovo x240 Screen Backlight not present

              Its very unlikely. I doubt your measurements. Are u sure about pin 26?? You are supposed to get +19V there. Btw, pin26-29 are together. Pin 13-14 is LCD VCC and it is expected to get 3V there. Check F3 as well.

                Comment

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