A guide to fixing/troubleshooting some common plasma TV problems

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  • capkid
    Badcaps Legend
    • Oct 2010
    • 1339
    • United States

    #361
    Re: A guide to fixing/troubleshooting some common plasma TV problems

    You can do a search on ShopJimmy.com to see if any substitutes are available.
    LG Plasma Mal-Discharge Correction Service

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    • Jason 82
      Member
      • Oct 2013
      • 11
      • USA

      #362
      Re: A guide to fixing/troubleshooting some common plasma TV problems

      I replaced one fuse on it and same issue.

      Comment

      • capkid
        Badcaps Legend
        • Oct 2010
        • 1339
        • United States

        #363
        Re: A guide to fixing/troubleshooting some common plasma TV problems

        You may have a faulty Y-Sus if the fuse blew. Here's what I'd do:

        (1) Check all Y-Sus and Z-Sus fuses.
        (2) Check all standard panel voltages:
        Power supply: VS and VA
        Y-Sus: VSC and -Vy
        Z-Sus: Vzb (aka Zbias)

        Edit:
        If you're unsure how to do the voltage checks, I can diagram them for you tonight. Also, there are lots of threads that mention the voltage checks specifically for LG-based TVs like yours.
        Last edited by capkid; 10-31-2013, 03:04 PM.
        LG Plasma Mal-Discharge Correction Service

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        • Jason 82
          Member
          • Oct 2013
          • 11
          • USA

          #364
          Re: A guide to fixing/troubleshooting some common plasma TV problems

          Yes, please do. I would much appreciate the diagram and I will check, I appreciate all the help. I'll stand by on ordering a z- sus board.

          Thanks

          Jason.

          Comment

          • capkid
            Badcaps Legend
            • Oct 2010
            • 1339
            • United States

            #365
            Re: A guide to fixing/troubleshooting some common plasma TV problems

            Ok, here you go. The voltage checks are listed on the pictures I've attached. The black and red arrows denote the black and red probes. If there is no black arrow included for a test point, that means your black probe should be placed on chassis ground (a metal part of the back of the TV is fine). Post a pic of the panel label that lists the voltages so we can help you compare your readings to the label.
            Attached Files
            Last edited by capkid; 10-31-2013, 09:46 PM.
            LG Plasma Mal-Discharge Correction Service

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            • jamie_ydr
              New Member
              • Oct 2013
              • 8
              • united states

              #366
              Re: A guide to fixing/troubleshooting some common plasma TV problems

              Tom. this is a great help. Thank you for taking the time to break it down..Although I do have a problem with a set that i am working on, that is real similiar to your posts.. I have a 50pfp5332d/37 and it came to me with sound and no picture. Normally i would do a little testing and then replace the x or y sustain boards.. Although I have been working to become more confident in component level repair. So guys with this being said voltages were a little off and i was thinking that something was dragging them down or bumping them up. so i've checked all fuses including the thru-hole and sm ..All fuses are good, so i was looking at the ysus and noticed that the voltage on the lower half was gone and like 1/2 of what things should have been.. Then I notice a mosfet or power ic 7 leg MR4720 is the part number marking and a pin is burned in half. so I have ordered a couple of them, only available from hong kong, and am waiting to see if this fixes the set.. I guess my question is DO YOU THINK SOMETHING OTHER THAN THIS PART CAUSED IT TO FAIL? I iwll let you know once that part arrives abd soldered in. Is there anything else I should look for? I will post a pic of the part and the location on the board tomorrow. thanks again jamie
              Last edited by jamie_ydr; 11-01-2013, 12:35 AM. Reason: wanted to add information

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              • Jason 82
                Member
                • Oct 2013
                • 11
                • USA

                #367
                Re: A guide to fixing/troubleshooting some common plasma TV problems

                Will do in the Am. Thank you. I appreciate the help !

                Comment

                • jamie_ydr
                  New Member
                  • Oct 2013
                  • 8
                  • united states

                  #368
                  Re: A guide to fixing/troubleshooting some common plasma TV problems

                  vinceroger69, thanks for the link there is some really good inforamtion here. thanks again..If anyone knows where i can get ccfl replacement tubes for sharp lc6554u sharp 65" i need ccfl. also if there is a way to trick the set into thinking it has the bulb please post or nessage me. I have one bad ccfl in the set and have moved it to the bottom of the screem but cant find a replacement and have a huge tv taking up space in repair area due to bad bulb..thanks jamie

                  Comment

                  • Jason 82
                    Member
                    • Oct 2013
                    • 11
                    • USA

                    #369
                    Re: A guide to fixing/troubleshooting some common plasma TV problems

                    Ok here are the pics of voltage
                    Attached Files

                    Comment

                    • Jason 82
                      Member
                      • Oct 2013
                      • 11
                      • USA

                      #370
                      Re: A guide to fixing/troubleshooting some common plasma TV problems

                      I changed the fuse that was blown on the toshiba and has not blown since, whst is the more complex issue?

                      Comment

                      • capkid
                        Badcaps Legend
                        • Oct 2010
                        • 1339
                        • United States

                        #371
                        Re: A guide to fixing/troubleshooting some common plasma TV problems

                        I would do the voltage checks to establish a baseline then worry about other possibilities afterwards.
                        LG Plasma Mal-Discharge Correction Service

                        Comment

                        • tom66
                          EVs Rule
                          • Apr 2011
                          • 32560
                          • UK

                          #372
                          Re: A guide to fixing/troubleshooting some common plasma TV problems

                          Originally posted by jamie_ydr
                          vinceroger69, thanks for the link there is some really good inforamtion here. thanks again..If anyone knows where i can get ccfl replacement tubes for sharp lc6554u sharp 65" i need ccfl. also if there is a way to trick the set into thinking it has the bulb please post or nessage me. I have one bad ccfl in the set and have moved it to the bottom of the screem but cant find a replacement and have a huge tv taking up space in repair area due to bad bulb..thanks jamie
                          Defeating the bulb detect can be done if you have a schematic of the inverters; do you? Best put this in your own thread.
                          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

                          • Jason 82
                            Member
                            • Oct 2013
                            • 11
                            • USA

                            #373
                            Re: A guide to fixing/troubleshooting some common plasma TV problems

                            Ok this is what I got
                            Vs-172.9
                            Va-55.4
                            VZb-.60
                            Vsc 1.26-9.94 fluctuated between these numbers
                            -Vy .7-1.5 fluctuated between these
                            Hope this helps us trouble shoot

                            Comment

                            • tom66
                              EVs Rule
                              • Apr 2011
                              • 32560
                              • UK

                              #374
                              Re: A guide to fixing/troubleshooting some common plasma TV problems

                              Your Vs is really low - unlikely to be your problem but do adjust it later.
                              -Vy and Vsc are faulty which indicates a Y-sustain fault.
                              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

                              • capkid
                                Badcaps Legend
                                • Oct 2010
                                • 1339
                                • United States

                                #375
                                Re: A guide to fixing/troubleshooting some common plasma TV problems

                                Agree with Tom. The Vzb is also low or not measured correctly. It should be 100V. When the fuse on the Y-Sus blows, it's usually an indication that the large IC under the big heat sink has shorted.

                                Video: http://www.youtube.com/watch?v=Y8MNQYXw8E0&sns=em
                                Last edited by capkid; 11-01-2013, 03:21 PM.
                                LG Plasma Mal-Discharge Correction Service

                                Comment

                                • tom66
                                  EVs Rule
                                  • Apr 2011
                                  • 32560
                                  • UK

                                  #376
                                  Re: A guide to fixing/troubleshooting some common plasma TV problems

                                  Good catch didn't see that.
                                  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

                                  • Jason 82
                                    Member
                                    • Oct 2013
                                    • 11
                                    • USA

                                    #377
                                    Re: A guide to fixing/troubleshooting some common plasma TV problems

                                    So not the z-sustain board. ?

                                    Comment

                                    • capkid
                                      Badcaps Legend
                                      • Oct 2010
                                      • 1339
                                      • United States

                                      #378
                                      Re: A guide to fixing/troubleshooting some common plasma TV problems

                                      At a minimum, your Y-Sus is bad. Your Z-Sus may also have issues if the Vzb voltage reading you posted is accurate. Typically, the recommendation is to replace the large IC on BOTH boards at the same time.
                                      LG Plasma Mal-Discharge Correction Service

                                      Comment

                                      • Merbesfield
                                        Clueless dude
                                        • Oct 2013
                                        • 25
                                        • USA

                                        #379
                                        Re: A guide to fixing/troubleshooting some common plasma TV problems

                                        Ok Tom, here are the pics of the back of my TV. To refresh, it is an LG. Model no. RU42PZ61. I have located the place to send the board for repair, but need to know which part I am supposed to remove.

                                        http://www.ebay.com/itm/6871QCH038A-...item2a22d26aa4

                                        So here is a pic of inside. This is with the small access panel removed. Do I have to remove the entire back or just the smaller access panel? How do I know which part I am after?
                                        Attached Files
                                        Trying to fix my: LG Model no. RU42PZ61

                                        Comment

                                        • Merbesfield
                                          Clueless dude
                                          • Oct 2013
                                          • 25
                                          • USA

                                          #380
                                          Re: A guide to fixing/troubleshooting some common plasma TV problems

                                          Here are some more pics.
                                          Attached Files
                                          Trying to fix my: LG Model no. RU42PZ61

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