(old) LG 32lk330 cycles Backlight 3 times and then OFF

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  • edugimeno
    Badcaps Veteran
    • May 2017
    • 581
    • Spain
    #1

    (old) LG 32lk330 cycles Backlight 3 times and then OFF

    Hi!! I have been given this old TV set.
    When I hit the power button, the BL (as you know this is a CFL backlight) turns on, video works fine as I can see the LG logo show off, but the backlight starts going on-off for 3 times, when it gives up and turns completly off
    This set has a inverter board on the top right corner. This inverter (or the tubes, I don't really know) buzzes very loudly during the second that the BL stays ON. I have posted a video, turn your volume UP!

    https://fileport.io/9EdfmD5qtEaw

    I have checked voltages at the PS
    All normal voltages (3.5, 12v, 24v) stay ON correctly during the power cycles
    INV ON pulses HI-LO during the power cycles. ERROR does the same
    If I disconnect the inverter board from the power board, INV_ON stays ON (3.3v) all the time, and ERROR pulses during the power cycles
    If I disconnect the CFL outputs from the inverter I get the same behaviour as above (like CFL conditions does not seem to affect). Also the led in the inverter board pulsus while these power cycling happen

    This TV is probably not worth much repair, but is this something a quick fix sounds feasible?
    Thanks!

    2 Photos
    Tags: None
    • nomoresonys
      Badcaps Legend
      • Jan 2013
      • 12172
      • U.S.
      #2
      Maybe check out the inverter, test everything you can on there, hows the fuse F1?, I might try changing out those 2 electrolytic caps, hard to tell if they are bad without a tester but it's something to try.

        Comment

        • edugimeno
          Badcaps Veteran
          • May 2017
          • 581
          • Spain
          #3
          Thanks! I tried resoldering some points (capacitors, large Q's) etc with no luck., I called the guy and told him that being such an old TV (not even LED BL) it wasn't worth the repair, so he's scraping it.
          Tjank you!

            Comment

            • nomoresonys
              Badcaps Legend
              • Jan 2013
              • 12172
              • U.S.
              #4
              Ok, right prolly not worth investing money in, I like those old sets but they are stupidly heavy compared to the newer ones.

                Comment

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