LG 50PJ350 - No pucture only Sound

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  • frankiek3
    New Member
    • May 2013
    • 5
    • USA
    #1

    LG 50PJ350 - No pucture only Sound

    A recent lightning storm took out a LG 50PJ350 TV (and a Cisco DPC3939 router), on to the LG 50PJ350:
    No picture but sound is working (through atsc coax input)
    Shorting 'Auto Gen' (LVDS and Main board cable disconnected) produces visible test pattern
    Control board LED on when only 5V Standby connected

    Main board suspected, surge possibly went through an hdmi input

    More to test and I'll update the thread when I do.

    I'd like to repair the components on the board then just swapping it. I haven't seen any visible signs of damage. Anyone successfully repair a main board like this? I'll be testing with a (hopefully) working main board just to be sure. So I should have a reference.

    Pictures and 'Training' Service Manual to be added on request.
    Tags: None
    • Alastair E
      Chief Womble
      • Mar 2013
      • 1963
      • U.K.
      #2
      Re: LG 50PJ350 - No pucture only Sound

      Just replace the board--Mains are notoriously difficult to trace faults on and to repair, as there's very little--often no schematics available for them, and any damage while de-soldering/replacing parts is normally fatal--as they are multi-layer boards.....

      save yourself the hassle--Just buy a replacement from a decent vendor...
      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

        • frankiek3
          New Member
          • May 2013
          • 5
          • USA
          #3
          Re: LG 50PJ350 - No pucture only Sound

          Well I haven't gotten the chance to dive into it as I was working on the router. I don't mind attempting a repair on the board since it would be scrap anyway.

          99% sure that the surge came in through the hdmi port (connected to a shutdown mac mini ).

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