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I need help LG 42pq3000

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    I need help LG 42pq3000

    6 months ago, (I know long time lol, been busy) I was living in lapland northern Finland and one night I forgot to unplug the tv from the mains. There was a lot of lightning that night and one of my friends tv`s failed also. It may be related as the tv was fine for 4 years before this occured.

    The morning after I switched on and noticed a loud noise a bit like the old dial up modems coming from the back of the tv. I watched it for 2 hours then switched off now it doesnt come back on. The red stand by light is evident then when you switch the power switch the lamp turns blue but tv just clicks and keeps trying to restart every now and then, screen is black and no sound apparent. Removing the back panel has revealed the dial up noise is from the y sus board when the system clicks and trys to power up.

    Im an auto electrician so I can use a dvom but im a total novice with plasmas.

    What I have done so far is remove the back panel and observe that the power supply board has a buzzing noise coming from a coil in the lower left corner, also this coil appears to have no voltage if i use an inductance voltage pen.
    The VA and VS voltages are 60V on 2 pins and 194V on 2 pins. However i can only get this voltage when tv is on if I unplug the harness from the power board to the Y sus board? I think its the Y sus its on the top left of the screen looking from the back, sorry im a novice as I said.

    Also i can only get 17 volts on both outputs from the power supply to the audio board again if the y sus is unplugged.

    I did check the diodes , resistors and capacitors on the power supply but they seem ok. I used an ohm meter to power the caps up then watched them discharge slowly on a volt meter.

    Any help appreciated I really cant afford another telly and I want to learn whats wrong with it.

    Thanks in advance , Ben
    Last edited by benfinland; 07-15-2013, 11:02 AM.

    #2
    Re: I need help LG 42pq3000

    Are you saying your VS/VA disappears if the Y-SUS is connected?
    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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      #3
      Re: I need help LG 42pq3000

      Hi Tom, yes if I measure the VA and VS at the power supply board I have the correct voltages across the 4 pins that is written on the inside of the television chassis on the label.

      BUT only if I disconnect the harness connector from the Y SUS as soon as I power off the TV and then reconnect the Y SUS , power back on the voltage disappears again as does the 17 volts across 2 pins of the 24 pin micro connector on the bottom right of the power board, the one that goes to the av board.

      Comment


        #4
        Re: I need help LG 42pq3000

        ive tried to get my head round the schematics lol, but cars are so easy compared to this stuff, I really want to understand how it all works but im confused so far.

        Comment


          #5
          Re: I need help LG 42pq3000

          Anyone? I guess I shall order a couple of boards as board tech is way beyond my skill level. I will let you now how i get on

          Comment


            #6
            Re: I need help LG 42pq3000

            The Y-SUS is most likely at fault. I believe repair kits for them are available.
            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


              #7
              Re: I need help LG 42pq3000

              yes I thought so as of it was shorted this could be why my voltage dissapears.

              Comment


                #8
                Re: I need help LG 42pq3000

                Look at the EAX or EBR number to find a replacement part or repair kit.
                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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