Samsung LN55C630K1F backlight issues

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  • matomato13
    Member
    • Sep 2016
    • 31
    • Canada

    #1

    Samsung LN55C630K1F backlight issues

    Hi everyone,

    I decided to start a new thread since the last one was more about the power board issue (which I replaced). Here's the link to the old thread.

    Here's a recap of the problems I am having now with the backlight.
    • There's two inverter boards on this TV, I previously purchased two replacement boards that I never used.
    • I always had problems with the backlight on this TV (before the power board blew up). Sometimes I opened the TV and it would work for a few minutes or hours and sometimes the backlight stopped working almost immediately. Sometimes fast movement on the screen would trigger the backlight to stop.
    • After replacing the power board, I left everything intact and the backlight would appear 2 seconds on power up and would disappear before I could see the image.
    • I decided to replace the inverter boards, but didn't screw them to the TV, just left them floating around on the cables. The TV would turn on and the backlight would work correctly if I left it on the HDMI input (not connected to anything so black screen). If I changed to analog TV input (with the "snow") the backlight would turn off after 1-2 seconds.
    • When the backlight was working on the HDMI input I could hear a buzzing noise coming from one of the transformer on the inverter board. The noise would lower when I lowered the backlight brightness in the menu.
    • I replaced the inverter board that was causing the noise, still leaving it hanging on to cables not touching the TV. No more buzzing noise but still the same problem, works with HDMI input and turns off with the analog TV input.
    • I left it 5-10 minutes on the HDMI input while I was doing something. Came back and changed to analog TV input and the backlight stayed open for a long time (turned off the TV before I could see it turn off by itself).
    • Decided to put back the screws on the inverter boards and now the backlight turns off just before the image is visible, just like before I decided to unscrew it.
    • I removed the screws, still working, put one screw back and no backlight (only the 2 seconds flash before image). The screw is, I think, used to ground the inverter boards (if you look at the image, you'll see what I mean).


    Here's a link to the two inverter boards
    http://www.shopjimmy.com/auo-19-54t0...t-inverter.htm
    http://www.shopjimmy.com/auo-19-54t0...t-inverter.htm

    So that's a good recap of where I am now.
  • matomato13
    Member
    • Sep 2016
    • 31
    • Canada

    #2
    Re: Samsung LN55C630K1F backlight issues

    Any help?

    Comment

    • Nick's Tvs
      Badcaps Veteran
      • Jan 2014
      • 621
      • USA

      #3
      Re: Samsung LN55C630K1F backlight issues

      Sounds like you have bad ccfl that will need to be replaced. This is going to be a very difficult, time consuming and delicate procedure as you will want to remove the screen from the set and take a look at your CCFL lamps. First I would set the brightness down as low as possible so that you may keep the backlight on when you plug it back in while the lamps are exposed. Then just look for any of them that may be dim, discolored or pinkish looking. You may have 1 or more bad lights.

      Comment

      • matomato13
        Member
        • Sep 2016
        • 31
        • Canada

        #4
        Re: Samsung LN55C630K1F backlight issues

        What do I do once I find the bad CCFL lamps? What can I find one for my TV model?

        Comment

        • matomato13
          Member
          • Sep 2016
          • 31
          • Canada

          #5
          Re: Samsung LN55C630K1F backlight issues

          Help? I couldn't find a disassembly guide for the TV either sonI can't get the part numbers for the ccfl.

          Comment

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