LG 50PM6700 Panel problem

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  • BigPete
    Senior Member
    • Jul 2012
    • 69
    • New Zealand
    #1

    LG 50PM6700 Panel problem

    I have a TV that had a faulty power supply. It was a 1250V 22nF cap.
    Replaced that and the TV ran fine for 2 days. Then stopped. Took it apart turns out it is the top buffer board that has failed.
    The model of the tv is 50PM6700. It is a 3D tv, but I have found it has the same panel as The PA4500 and PA6500 and probably others. I looked for the plastic tab that breaks and cuts into the ribbon cable on the top but can't find it. My Tv may have a different frame that eliminated that problem.
    The top IC on the buffer tested bad. What is the chance of it being just the buffer. From what I read it looks low.
    Cheers

    Pete
    Tags: None
    • tom66
      EVs Rule
      • Apr 2011
      • 32560
      • UK
      #2
      Re: LG 50PM6700 Panel problem

      Did you ever get a line running left to right? If not, you MAY be lucky... Check the ribbon for damage (it will be hard to see, but if you bend the ribbon back you'll typically be able to see a little tear in it)
      Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
      For service manual, schematic, boardview (board view), datasheet, cad - use our search.

        Comment

        • Alastair E
          Chief Womble
          • Mar 2013
          • 1963
          • U.K.
          #3
          Re: LG 50PM6700 Panel problem

          Pull the buffer out of the set. Make sure the screen-tabs are not touching any metalwork, and all screws that hold all the other boards are fitted and snug--and fire her up....

          IF the Y-SUS, PSU, Z-SUS etc is OK, you'll have correct Vs, Va VSC and -Vy voltages along with sound. This will indicate all is well and just a buffer should do it

          (--No picture obviously without buffer.....)
          TELEFIX

          How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
          http://www.irf.com/technical-info/appnotes/an-1088.pdf
          PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

            Comment

            • BigPete
              Senior Member
              • Jul 2012
              • 69
              • New Zealand
              #4
              Re: LG 50PM6700 Panel problem

              No, never got a line. Was watching one night then turned it off. In the morning it wouldn't turn on.
              With the top buffer out the bottom half of the screen turns on with sound.
              If the line is the indication, i'll try and source another buffer board.
              Cheers.

                Comment

                • tom66
                  EVs Rule
                  • Apr 2011
                  • 32560
                  • UK
                  #5
                  Re: LG 50PM6700 Panel problem

                  I don't guarantee it'll show the line before failure, but on all the other sets over I've seen all users reported seeing a line before failure. I would suggest checking that ribbon first though.
                  Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                  For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                    Comment

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