42LG300 backlight issue

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  • netdent
    Badcaps Veteran
    • May 2011
    • 208

    #1

    42LG300 backlight issue

    Have the above tv with a backlight fault, lights at switch on for a few seconds then dims and flickers and goes off, has a good 24volt supply.

    this set has twin invertors so not sure how to isolate the fault to a particular board slave or master.

    any advice welcome

    thanks Ronnie
    sigpic
  • Dgtech
    E. Technician
    • Apr 2009
    • 1462
    • Steeler

    #2
    Re: 42LG300 backlight issue

    Might be transformers on inverter or a bunch of other things. No way to be sure right now, especially without pictures.
    The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

    Comment

    • netdent
      Badcaps Veteran
      • May 2011
      • 208

      #3
      Re: 42LG300 backlight issue

      Originally posted by Dgtech
      Might be transformers on inverter or a bunch of other things. No way to be sure right now, especially without pictures.
      Cheers Dgtech, seems to have resolved itself for no reason other than removing and refitting the 2 invertors? on soak test to see if problem reappears!

      Ronnie
      sigpic

      Comment

      • randtek
        Badcaps Veteran
        • Oct 2011
        • 280
        • US

        #4
        Re: 42LG300 backlight issue

        Many inverter issues on various makes and models of TV seem to be due to poor grounding between inverter board, screws, and panel (ground). They will go away if you remove and replace the board, as it disturbs the connection. Howver, thes problems usually return. To make sure the problem does not come back, you should take the inverters back off, and lightly dress (clean) all circuit connections to the screw holes on the inverter, using fine sandpaper. Also do the same around screw holes on the shields for the inverters, and the backs of the screw heads themselves. Once all of these connections have been dressed, reassemble and enjoy.

        Comment

        • netdent
          Badcaps Veteran
          • May 2011
          • 208

          #5
          Re: 42LG300 backlight issue

          Originally posted by randtek
          Many inverter issues on various makes and models of TV seem to be due to poor grounding between inverter board, screws, and panel (ground). They will go away if you remove and replace the board, as it disturbs the connection. Howver, thes problems usually return. To make sure the problem does not come back, you should take the inverters back off, and lightly dress (clean) all circuit connections to the screw holes on the inverter, using fine sandpaper. Also do the same around screw holes on the shields for the inverters, and the backs of the screw heads themselves. Once all of these connections have been dressed, reassemble and enjoy.
          thankyou for that advice, will look at this while the back is still off

          thanks Ronnie
          sigpic

          Comment

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