LG 32Ln5400 tv, backlight problem

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  • Ally
    New Member
    • Oct 2016
    • 4
    • England
    #1

    LG 32Ln5400 tv, backlight problem

    Hi, I need some help with an LG tv, it's 32 inch LN5400. I'm brand new to all things electrical, so apologies in advance for my lack of tech knowledge. I'm keen to learn more and have been reading up and watching videos etc.

    The tv has the sound but no picture problem. Screen is totally black, doesn't blink on or anything. I've done the flash light test and can see the lg logo faintly on screen. I have removed the back and replaced the power supply with a new one but it was still the same. I read up some more and have now tested the power supply board with a multimeter. The readings for the wires going to the main board and to the led strips seem to be right.

    So with the led strips I have used the multimeter in diode mode and tested the ends of the strips and am getting the beep which means they are working? I have also scratched away a bit of plastic either side of each LED to test each one. All are lighting up except I can't seem to get the ones on the far end of the strips to light. I can't imagine it would be just the end ones on all three strips that are blown? I am getting a beep on these end ones though.

    Can anyone advise what may be the issue and also perhaps I am testing these end leds wrong?

    Thanks a lot.
    Tags: None
    • budm
      Badcaps Legend
      • Feb 2010
      • 40746
      • USA
      #2
      Re: LG 32Ln5400 tv, backlight problem

      Lets us see some pictures of what we are dealing with and where the test points you have made.
      Never stop learning
      Basic LCD TV and Monitor troubleshooting guides.
      http://www.badcaps.net/forum/showthr...956#post305956

      Voltage Regulator (LDO) testing:
      http://www.badcaps.net/forum/showthr...999#post300999

      Inverter testing using old CFL:
      http://www.badcaps.net/forum/showthr...er+testing+cfl

      Tear down pictures : Hit the ">" Show Albums and stories" on the left side
      http://s807.photobucket.com/user/budm/library/

      TV Factory reset codes listing:
      http://www.badcaps.net/forum/showthread.php?t=24809

        Comment

        • Ally
          New Member
          • Oct 2016
          • 4
          • England
          #3
          Re: LG 32Ln5400 tv, backlight problem

          Here is the leds and where I've scratched to test them, with the end ones not coming on.
          Attached Files

            Comment

            • budm
              Badcaps Legend
              • Feb 2010
              • 40746
              • USA
              #4
              Re: LG 32Ln5400 tv, backlight problem

              So you test each LED one by one and found that one of them does not light up, is that it? If it is then you found the problem.
              Never stop learning
              Basic LCD TV and Monitor troubleshooting guides.
              http://www.badcaps.net/forum/showthr...956#post305956

              Voltage Regulator (LDO) testing:
              http://www.badcaps.net/forum/showthr...999#post300999

              Inverter testing using old CFL:
              http://www.badcaps.net/forum/showthr...er+testing+cfl

              Tear down pictures : Hit the ">" Show Albums and stories" on the left side
              http://s807.photobucket.com/user/budm/library/

              TV Factory reset codes listing:
              http://www.badcaps.net/forum/showthread.php?t=24809

                Comment

                • Ally
                  New Member
                  • Oct 2016
                  • 4
                  • England
                  #5
                  Re: LG 32Ln5400 tv, backlight problem

                  All are lighting up except the last ones on all three strips. Have I put the scratches in the right place? I want to make sure they are all working before putting the tv back together, as then I guess it's a problem with one of the boards?

                  Do you have a guess at what the problem might likely be with no backlight coming on?

                  Thanks again for your help.

                    Comment

                    • flocko
                      Badcaps Legend
                      • Nov 2012
                      • 1121
                      • uk
                      #6
                      Re: LG 32Ln5400 tv, backlight problem

                      The end LEDs return is via the thin trace along the side of the strip check eBay item for repair 252529898655

                        Comment

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