lg 32LC46 backlight inverter board fault

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  • jimbofz
    Badcaps Veteran
    • Apr 2013
    • 537
    • uk

    #21
    Re: lg 32LC46 backlight inverter board fault

    Originally posted by biruslapio
    that's probably the forum's auto resizer.

    So you must have an inverter fault, there is no way all the lamps aged uniformly and got darker on one side.

    What's the voltage on error, on/off, i-pwm and e-pwm?

    One of these pwm voltages controls the lamp brightness, if this is the same as other old lg lcds, 3.3v should be maximum brightness, and less than 0.8v it doesn't even turn on.

    These wires that you used for bypassing the error pin, they're too long, try using the least amount of wire you can, if nothing changes, i suggest replacing the inverter board, it's cheap at least.
    e pwm =4.1v i pwm= 3.3v on/off=4.9v error =0v

    Comment

    • jimbofz
      Badcaps Veteran
      • Apr 2013
      • 537
      • uk

      #22
      Re: lg 32LC46 backlight inverter board fault

      replacing board ? wheres the fun in that ,
      this tv is only worth peanuts due to its age
      but i enjoy the challenge of fault finding down to component level .
      its the best way to learn
      and this tv despite its age ic capable of good clear hd pics
      seasons greetings to all

      Comment

      • Biruslapio
        Badcaps Veteran
        • Nov 2013
        • 552
        • Brasil

        #23
        Re: lg 32LC46 backlight inverter board fault

        The voltages sent from main board are correct, it is the inverter that is at fault, maybe even a replacement board costing around 7 USD is not worth it on UK? Plus there's shipping.

        What about those 0 OHM resistors, are they fine? There should be no voltage drop on any of them, not much else to suggest here.

        Comment

        • jimbofz
          Badcaps Veteran
          • Apr 2013
          • 537
          • uk

          #24
          Re: lg 32LC46 backlight inverter board fault

          Originally posted by Biruslapio
          The voltages sent from main board are correct, it is the inverter that is at fault, maybe even a replacement board costing around 7 USD is not worth it on UK? Plus there's shipping.

          What about those 0 OHM resistors, are they fine? There should be no voltage drop on any of them, not much else to suggest here.
          thanks for trying all zero ohm components checked
          still a work in progress ,i will post the results

          Comment

          • jimbofz
            Badcaps Veteran
            • Apr 2013
            • 537
            • uk

            #25
            Re: lg 32LC46 backlight inverter board fault

            finally fixed inverter board fault
            47 ohm r76 was o/c causing shading left to right
            its across d12

            Comment

            • dick_barton
              Badcaps Legend
              • Aug 2015
              • 6642
              • Wales

              #26
              Re: lg 32LC46 backlight inverter board fault

              Well done. Persistance paid off.
              Willing to help but I'm no expert.

              Comment

              • jimbofz
                Badcaps Veteran
                • Apr 2013
                • 537
                • uk

                #27
                Re: lg 32LC46 backlight inverter board fault

                Originally posted by dick_barton
                Well done. Persistance paid off.
                im like a dog with a bone

                Comment

                • dskall
                  Badcaps Legend
                  • Oct 2016
                  • 2905
                  • usa

                  #28
                  Re: lg 32LC46 backlight inverter board fault

                  Originally posted by jimbofz
                  im like a dog with a bone
                  Well, it's good you didn't bury it and just keep gnawing on it.
                  I assume no responsibility for any stupid suggestions I might post.

                  Comment

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