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    Lg 60pk790 no picture

    Hi all, needing a little help if possible please.

    I've got an LG 60PK790 tv which has lost its picture and sound. When you turn the tv on everything acts as normal, the red standby light turns to blue, the screen flickers 'very dim' but looks like it's about to come on but that's it! If you press any button on the remote the blue led light responds as normal. If you turn all the lights off you can see the screen very dimly lit.

    So far I've, replaced the 3 main resistors R927, R928 and R929 on the power board which is an EAX61300501. I did this before checking the voltages 'trying to be clever'??
    After this obviously didn't work I checked all the vs and va voltages which were all correct and to spec, 202va and 60vs and the others 5v, the old resistors were fine measuring 10.6 .
    So next I unhooked the xsus, checked it for shorts but couldn't find anything obvious, the problem was still apparent with the xsus was unplugged. After this I unplugged the buffer boards, removing the top left the dim screen lit on the bottom and vice versa, so obviously not them. I then checked the ysus for shorts and couldn't find anything obvious but because I found a board for only£20 , which came out of a known working tv, I grabbed it and fitted it and, yep, nothing!
    Before I allow anymore money into the tv I'd just like to get other folks opinions.

    The tv went like this one day for no apparent reason, and the tv has not been dropped and shows no signs of damage when partially lit.


    Any help would be appreciated.

    #2
    Re: Lg 60pk790 no picture

    Forgot to add that, the bluray player will automatically switch the tv on and choose the right hdmi channel, or at least I presume it does, I've cycled through the other av channels and tried turning the tv up but no sound on any.
    Cheers

    Comment


      #3
      Re: Lg 60pk790 no picture

      Tried to take a picture but wasn't very good.
      The TV is a constant dull white not fuzzy, that's just what the camera picked up. It's also the full screen without any black patches.
      Attached Files

      Comment


        #4
        Re: Lg 60pk790 no picture

        Ok, right in the middle of the TV there's a smaller green board. This is the control board. It will connect most of the other boards in the set together, including the A/V board (has HDMI ports on it)

        Can you get a photo of this board... it needs to be of your board.
        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


          #5
          Re: Lg 60pk790 no picture

          This is the board fitted Tom.
          Attached Files

          Comment


            #6
            Re: Lg 60pk790 no picture

            Was there a reason you wanted to see it?

            Comment


              #7
              Re: Lg 60pk790 no picture

              Yes...

              Bottom right corner of the board, there are two points, next to R51 and R52 and a silver capacitor

              Test patterns can be enabled:

              - Unplug the power to the set
              - Put a wire link across the points R51 & R52, they need to be connected
              - Unplug the thick ribbon cable marked P31, to remove it squeeze the ends and pull gently
              - Plug in the power to the set, and if necessary press the power button to take it out of standby.

              Once the screen starts to glow, you may see a sequence of test patterns like so:
              https://www.youtube.com/watch?v=9LcqLM5TRHk

              Do you? The patterns may vary slightly from the video but in general they should look good with no dead pixels, stuck pixels, dead regions, or poor/incorrect colouration.
              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


                #8
                Re: Lg 60pk790 no picture

                Here's the results. Few lines but they go, however the solid line stays. What does this mean Tom?
                Cheers for replying.
                Attached Files

                Comment


                  #9
                  Re: Lg 60pk790 no picture

                  Bad plasma panel I'm afraid.... it's dead
                  Did you unplug/plug anything in whilst the set was live or shortly afterwards as this would kill the panel
                  Also possible that you were given a set with a dud panel

                  In general LGs seem to be the worst for plasma panel problems, although at least it's better than a crappy Samsung LED panel :/
                  Last edited by tom66; 10-27-2014, 03:50 PM.
                  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


                    #10
                    Re: Lg 60pk790 no picture

                    No nothing. Is it definitely gone then?

                    Comment


                      #11
                      Re: Lg 60pk790 no picture

                      Sorry... it's dead
                      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


                        #12
                        Re: Lg 60pk790 no picture

                        On reflection, when trying to fix the problem someone advised to update the software so I plugged the usb in but obviously couldn't see what it was doing. Could this have made the problem worse?

                        Comment


                          #13
                          Re: Lg 60pk790 no picture

                          It wouldn't have killed the panel, if that's what you're asking...
                          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


                            #14
                            Re: Lg 60pk790 no picture

                            Thank you for all your help Tom, as much as I'm upset about the overall verdict I really appreciate the time you've taken to help. Thank you!

                            Comment

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