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LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

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    LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

    I have an LG 55UJ6200 that cycles between sickly green, full color and back again with some lines and random banding at the top of the screen. After watching https://www.youtube.com/watch?v=pfrRhw7-ZII I was motivated to attempt this right away and got some pretty good success. I am using a huge piece of tape blocking a whopping 20 pins on the second cable in the tv. Only problem is after about 40 minutes or so the set gives a little random flicker - enough to be distracting. I am making this post to see if anyone has had a similar failure with this model and what pins are the ideal ones to block and which to never block. Might be quicker than trial and error.

    Now in the video he is able to cut down his tape and isolate the issue to just one pin. Now that's difficult in my opinion as you must slice the tape off the cable and risk cutting the traces so I am applying the tape a little bit at a time. Here are the before pics.
    Attached Files

    #2
    Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

    AFTER results. Also I have included a picture of the tape amount I used as well as a picture of the connector coming out of the mainboard in case someone can advise based on what they see for my next attempt.

    The panel does not appear to be cracked but there is a short in it somewhere based on what I've heard from youtubers. These modern panels are flimsy if they can't even last 3 years under normal use. Total power on hours: 918
    Attached Files

    Comment


      #3
      Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

      So these are the corresponding connections I am blocking in the signal for the best result so far.
      Attached Files

      Comment


        #4
        Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

        After testing for more than an hour the flicker has returned. So the tv will function for the length of a tv show before it shows issues. Also I got the power on hour count wrong, it was actually 619 hours. How ridiculous is that for durability?
        Last edited by Noobwithamultimeter; 05-06-2021, 06:30 PM. Reason: forgot something

        Comment


          #5
          Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

          You can try testing resistance of the MLCC (Multi Layer Ceramic Capacitors) on the tab bonding boards to see if any of them show low resistance reading.
          Never stop learning
          Basic LCD TV and Monitor troubleshooting guides.
          http://www.badcaps.net/forum/showthr...956#post305956

          Voltage Regulator (LDO) testing:
          http://www.badcaps.net/forum/showthr...999#post300999

          Inverter testing using old CFL:
          http://www.badcaps.net/forum/showthr...er+testing+cfl

          Tear down pictures : Hit the ">" Show Albums and stories" on the left side
          http://s807.photobucket.com/user/budm/library/

          TV Factory reset codes listing:
          http://www.badcaps.net/forum/showthread.php?t=24809

          Comment


            #6
            Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

            Originally posted by budm View Post
            You can try testing resistance of the MLCC (Multi Layer Ceramic Capacitors) on the tab bonding boards to see if any of them show low resistance reading.
            Ok I'll try if I get into it further, but for now I've noticed I can make the flicker go away if I use a smaller piece of tape. But when I do this the fine lines appear more noticeable. So it's a tradeoff between flickers or fine lines. I think I prefer the fine lines, flicker is much more distracting.

            Comment


              #7
              Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

              I don't want to remove it now since I've got a good image going, so here is a picture in case I change it. Appears to be first 12 pins covered.
              Attached Files

              Comment


                #8
                Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                Originally posted by budm View Post
                You can try testing resistance of the MLCC (Multi Layer Ceramic Capacitors) on the tab bonding boards to see if any of them show low resistance reading.
                I'd have to take a apart the frame to get at them. Are they repairable/replaceable?

                Comment


                  #9
                  Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                  Bad caps can be replaced if you have experience with SMD repair and have proper tools.
                  Example of bad MLCC:
                  https://www.badcaps.net/forum/showth...44#post1043044
                  Last edited by budm; 05-07-2021, 03:30 PM.
                  Never stop learning
                  Basic LCD TV and Monitor troubleshooting guides.
                  http://www.badcaps.net/forum/showthr...956#post305956

                  Voltage Regulator (LDO) testing:
                  http://www.badcaps.net/forum/showthr...999#post300999

                  Inverter testing using old CFL:
                  http://www.badcaps.net/forum/showthr...er+testing+cfl

                  Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                  http://s807.photobucket.com/user/budm/library/

                  TV Factory reset codes listing:
                  http://www.badcaps.net/forum/showthread.php?t=24809

                  Comment


                    #10
                    Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                    Crazy. I have it narrowed down to 4 leads covered now. Working on a smaller and smaller piece of tape. Color is correct but there are lines still. Getting very tricky with these tiny pieces of tape.

                    Comment


                      #11
                      Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                      Originally posted by Noobwithamultimeter View Post
                      Crazy. I have it narrowed down to 4 leads covered now. Working on a smaller and smaller piece of tape. Color is correct but there are lines still. Getting very tricky with these tiny pieces of tape.
                      Can you trace where they feed too ?
                      Please Do Not PM My Page Asking For Help Badcaps Is The Place For Advise, Page Linked For Business Reasons Only. Anyone Doing So Will Be Banned Instantly !

                      https://www.facebook.com/Telford-Tel...7894576335359/

                      Comment


                        #12
                        Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                        My best guess is pins 11-14 are affected because I can see a solid image with them blocked, although there are quite a few lines in the image. Also the color is correct. Blocking other lines causes the left side of the image to go kind of slightly lime green due to the yellow being off instead of yellow.

                        Here is where I think the lines lead to on the mainboard. There is no t-con board in this set.
                        Attached Files

                        Comment


                          #13
                          Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                          The lines pull though a via to the other side of the pcb a magnifying glass would be a big help, they also feed too another part of the board on the top. I’ve seen even the smallest of MLCCZ caps fail short, easy to test multimeter on ground and measure each side.
                          Please Do Not PM My Page Asking For Help Badcaps Is The Place For Advise, Page Linked For Business Reasons Only. Anyone Doing So Will Be Banned Instantly !

                          https://www.facebook.com/Telford-Tel...7894576335359/

                          Comment


                            #14
                            Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                            So it's possible the failure is mainboard related? Could be a mlcc on the mainboard or on one of the gate driver tabs? I think the tabs are very tricky to solder on.

                            Comment


                              #15
                              Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                              Originally posted by Noobwithamultimeter View Post
                              My best guess is pins 11-14 are affected because I can see a solid image with them blocked, although there are quite a few lines in the image. Also the color is correct. Blocking other lines causes the left side of the image to go kind of slightly lime green due to the yellow being off instead of yellow.

                              Here is where I think the lines lead to on the mainboard. There is no t-con board in this set.
                              LCD TV will have T-CON. It can be stand alone T-CON board, integrated T-CON into the LCD panel, or integrated T-CON into the main board.
                              Can we see the pictures of the whole back side of the TV showing all the board.
                              Never stop learning
                              Basic LCD TV and Monitor troubleshooting guides.
                              http://www.badcaps.net/forum/showthr...956#post305956

                              Voltage Regulator (LDO) testing:
                              http://www.badcaps.net/forum/showthr...999#post300999

                              Inverter testing using old CFL:
                              http://www.badcaps.net/forum/showthr...er+testing+cfl

                              Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                              http://s807.photobucket.com/user/budm/library/

                              TV Factory reset codes listing:
                              http://www.badcaps.net/forum/showthread.php?t=24809

                              Comment


                                #16
                                Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                                You’ve almost narrowed it down to the panel, start doing some resistance checks.
                                Please Do Not PM My Page Asking For Help Badcaps Is The Place For Advise, Page Linked For Business Reasons Only. Anyone Doing So Will Be Banned Instantly !

                                https://www.facebook.com/Telford-Tel...7894576335359/

                                Comment


                                  #17
                                  Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                                  The mlcc's are integrated into the panel. Only problem is I'm nervous about getting the outer frame off as I can't find any youtube guides on this model yet, also once I get there I have no replacement capacitors.

                                  Comment


                                    #18
                                    Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                                    Put the Tv on the table on a cloth screen upwards, go around it take the screws out, remove the frame bit by bit or if it’s a solid frame start lifting at the end opposite to the drivers and pcb. Needle DMM probes are advised as you don’t want to put a load of pressure of the small parts with larger probes. I’ve fixed a SONY 55” 4K set that had 1 shorted ceramic cap in a bank of like 20 in parallel it takes time, having an LCR meter can help track down the lowest point of resistance too.
                                    Please Do Not PM My Page Asking For Help Badcaps Is The Place For Advise, Page Linked For Business Reasons Only. Anyone Doing So Will Be Banned Instantly !

                                    https://www.facebook.com/Telford-Tel...7894576335359/

                                    Comment


                                      #19
                                      Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                                      Ok back at the frame removal, here is a photo of the whole back and I've indicated what line I've been tape masking with different results.
                                      Attached Files

                                      Comment


                                        #20
                                        Re: LG 55UJ6200 BEFORE & AFTER tape fix/fine tuning success

                                        So I removed one long metal guard along the bottom of the screen and when I looked at the sides there appear to be no gate drivers on the left and right sides of the TV. So I am going to focus on the left side of the panel first since I think that is the side that is affected.

                                        Comment

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