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Lg plasma problem please help

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    Lg plasma problem please help

    Hello all, I have an lg 50pk550 plasma tv. It's worked
    Fine for about 2 years now. A couple days ago, I tried to turn
    It on and it clicked, the screen lit up and it looked like it was
    Going to turn on like normal but then it clicked and shut
    Off. After a few seconds it clicked again and tried to turn on again
    All on its own. I removed the back panel and could not see
    Anything obvious (no blown caps, resistors, fuses etc).
    I grabbed my meter and began checking voltages and this is
    Where I would like to pick someone's brain with some expertise
    Working on these tvs. One interesting thing I want to point
    Out is that now whenever I plug in the ac to the wall, the tv
    Clicks and tries to turn on without pressing the on button. Any
    Ideas? I was able to find a place that carries this model power
    Supply but I'm not so sure this is my problem.

    #2
    Re: Lg plasma problem please help

    If I remember the jist of this block of videos:
    http://www.youtube.com/channel/UCPCE...sort=dd&view=0
    one or both of the power resistors in the upper right-hand corner (when it's installed in the TV) of the power board start to head south, I think they were 22 ohm and rated for 5 watts. That would be my first check.
    That in turn can possibly cause a 6-pin voltage regulator, a diode near that regulator and fuse near them to all give up the ghost. That would be next.
    Last edited by Rack; 02-11-2013, 08:02 PM.

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      #3
      Re: Lg plasma problem please help

      I really appreciate your help and advice! I was leaning towards just replacing the entire power supply but I got thrown off because of how the tv tries to turn on simply by plugging it into the wall. I found some schematics for this and it seems like the power supply gets a standby signal (ground) from the main processor. If this ground is floating (missing) it will automatically try to boot up when plugged in. And this is what it's doin? So I thought that maybe the main processor pcb is bad but I'm not sure?

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        #4
        Re: Lg plasma problem please help

        I know of several TVs (indeed, most) that will attempt to power on immediately after power is removed. If the TV had a problem perhaps this is what occurred and it is just trying to resume power?
        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.

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          #5
          Re: Lg plasma problem please help

          I have this model tv and it doesnt power on, just clicks then red light comes on and i push it again, it clicks then the red light fades.

          i have this particular tv with the psu board number
          EAX61392501/8

          i checked the big white resistors and all 3 have the 10ohm resistance. the diode located by the resistor and voltage regulator is giving me straight continuity both ways.

          am i to assume that because this diode is bad , that the voltage regulator is bad as well?
          thanks

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