Clueless Novice- Troubleshooting 50" LG PX950 No Picture or Sound

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  • Alittleevil
    New Member
    • Jan 2015
    • 5
    • United States
    #1

    Clueless Novice- Troubleshooting 50" LG PX950 No Picture or Sound

    Hi all. i've been reading through some threads on here over the past week trying to repair my LG set. I took a basic electronics course in college a few years ago, and that's about the extent of my knowledge in the field.

    So about a week ago, my tv picture went out. While on, the picture unexpectedly flickered a couple horizontal lines (resembled a bad satellite signal) turned off and the tv restarted itself. Odd. The set and the picture came back on, so I disregard the incident. Then a few moments later it cycled off and on again. The third time was shortly after the second only this time the picture never came back on. Now, the TV powers on but has no picture or sound.

    After reading up a bit here, I opened up the set. Checked all the fuses, they seem ok. Checked some voltages on the PSU and they seemed fine.

    Talked to a guy in a local repair shop and he said it sounds like my panel is bad and I should toss the set or scrap it.

    I am tight on funds and cannot currently afford a replacement TV or an expensive repair. Would have loved to just replace the PSU and have my TV working for a Super Bowl party I'm throwing this coming weekend. Instead, it looks like I'll be showing the big game on a tiny 28" set.

    Thanks in advance for any help.
    Last edited by Alittleevil; 01-27-2015, 03:53 PM.
    Tags: None
    • tom66
      EVs Rule
      • Apr 2011
      • 32560
      • UK
      #2
      Re: Clueless Novice- Troubleshooting 50" LG PX950 No Picture or Sound

      Can you take the back cover off your set and get some pictures of the parts inside your TV? We can then go from there.

      Do you have a digital multimeter 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

        • Alittleevil
          New Member
          • Jan 2015
          • 5
          • United States
          #3
          Re: Clueless Novice- Troubleshooting 50" LG PX950 No Picture or Sound

          Pictures

          I do own a multimeter.

            Comment

            • tom66
              EVs Rule
              • Apr 2011
              • 32560
              • UK
              #4
              Re: Clueless Novice- Troubleshooting 50" LG PX950 No Picture or Sound

              OK, do you see any points marked Vs_TP, Va_TP or similar on the power board? Check you get about 200V for Vs, 60V for Va
              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

                • selldoor
                  Slow Learner
                  • Dec 2010
                  • 7870
                  #5
                  Re: Clueless Novice- Troubleshooting 50" LG PX950 No Picture or Sound

                  Pictures are not really clear enough for troubleshooting you need more light and no flash. They should be posted using manage attachments so they are available to help others in furure.
                  Please upload pictures using attachment function when ask for help on the repair
                  http://www.badcaps.net/forum/showthread.php?t=39740

                    Comment

                    • tom66
                      EVs Rule
                      • Apr 2011
                      • 32560
                      • UK
                      #6
                      Re: Clueless Novice- Troubleshooting 50" LG PX950 No Picture or Sound

                      There's nothing wrong about imgur, they're pretty good at keeping photos up. Better than imageshack, tinypic, etc...
                      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

                        • Alittleevil
                          New Member
                          • Jan 2015
                          • 5
                          • United States
                          #7
                          Re: Clueless Novice- Troubleshooting 50" LG PX950 No Picture or Sound

                          Originally posted by tom66
                          OK, do you see any points marked Vs_TP, Va_TP or similar on the power board? Check you get about 200V for Vs, 60V for Va
                          Vs all = 204.5V
                          Va = 60.9V


                          Would it be helpful to retake pictures? I uploaded the previous ones using an iPad to take pictures but i'll take the time to upload some off a better digital camera if would be of help.

                            Comment

                            • tom66
                              EVs Rule
                              • Apr 2011
                              • 32560
                              • UK
                              #8
                              Re: Clueless Novice- Troubleshooting 50" LG PX950 No Picture or Sound

                              A clearer photo of the Y-sustain and Z-sustain boards may help.

                              Is there an LED lit on the control board? (This is one of the boards below the power supply board. It connects to many of the other boards in the TV.)
                              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

                                • Alittleevil
                                  New Member
                                  • Jan 2015
                                  • 5
                                  • United States
                                  #9
                                  Re: Clueless Novice- Troubleshooting 50" LG PX950 No Picture or Sound

                                  There is a green LED on the control board. It blinks on/off twice every 4-5 seconds.

                                  I will attempt to upload better pictures of the sustain boards tomorrow under sunlight as my indoor lighting is making clear pictures difficult.

                                  Thank you Tom and Selldoor for your patience and aide so far.

                                    Comment

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