lg 47lx6500 backlight with sound no display

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  • storexxm
    Senior Member
    • Oct 2012
    • 107
    • Vienna

    #21
    Re: lg 47lx6500 backlight with sound no display

    another news... when i disconect the lower connection from the main bord the beeping is gone... seems like there were just the speakers
    BUT i saw that the short picture when starting the tv are fine vertical lines...
    when i turn the tv on and off via plug the backlight switches on and off two times.
    with remote control on and off everything is the same BUT the backlight wont start any time...
    Attached Files

    Comment

    • nomoresonys
      Badcaps Legend
      • Jan 2013
      • 12075
      • U.S.

      #22
      Re: lg 47lx6500 backlight with sound no display

      Is this LC470EUS-SCA1 your panel number? is on a sticker on back metal panel sometimes hard to see.

      Comment

      • storexxm
        Senior Member
        • Oct 2012
        • 107
        • Vienna

        #23
        Re: lg 47lx6500 backlight with sound no display

        Originally posted by nomoresonys
        Is this LC470EUS-SCA1 your panel number? is on a sticker on back metal panel sometimes hard to see.
        yes exactly.... why ?

        Comment

        • budm
          Badcaps Legend
          • Feb 2010
          • 40746
          • USA

          #24
          Re: lg 47lx6500 backlight with sound no display

          Disconnect able to the T-CON board and see what will happen, you will get nothing on the screen of course.
          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

          • storexxm
            Senior Member
            • Oct 2012
            • 107
            • Vienna

            #25
            Re: lg 47lx6500 backlight with sound no display

            already tried... instead of those lines just a black screen with backlight... but backlight wonst stay on.. so.. no change ;/

            Comment

            • nomoresonys
              Badcaps Legend
              • Jan 2013
              • 12075
              • U.S.

              #26
              Re: lg 47lx6500 backlight with sound no display

              .
              Last edited by nomoresonys; 08-03-2020, 10:15 PM.

              Comment

              • budm
                Badcaps Legend
                • Feb 2010
                • 40746
                • USA

                #27
                Re: lg 47lx6500 backlight with sound no display

                https://www.badcaps.net/forum/attach...0&d=1596474706
                So some one did work on the power supply board and did a bad soldering works on the board.
                Right now you may have multiple problems and we do not know if other boards are also worked on.
                You can try fixing the power supply board first so you can get the backlights to come on and stay on and hope that backlights LED's are OK.
                I would clean up that soldering works first, it looks like the through hole legs are not solderer properly, I also cannot tell what the MOSFET was replaced or not and if it is replaced with the correct one or not.
                This TV can be a can of worm since we do not know what other bad works were done to the TV.
                If you want to try to fix the power supply board then I will need good clear straight shots pictures of the whole top and bottom side of the power supply board, it is hard to trace the circuit when pictures are shown in sections.
                Last edited by budm; 08-03-2020, 10:44 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

                • storexxm
                  Senior Member
                  • Oct 2012
                  • 107
                  • Vienna

                  #28
                  Re: lg 47lx6500 backlight with sound no display

                  here are further shots of the tv-
                  hope u can see whats going on there
                  i will try to find out what the pre owner did to this tv
                  Attached Files

                  Comment

                  • budm
                    Badcaps Legend
                    • Feb 2010
                    • 40746
                    • USA

                    #29
                    Re: lg 47lx6500 backlight with sound no display

                    OK, much better pictures, thanks.
                    The section that was worked on is part of LED backlights power supply.
                    I will study the power supply board further and see if it can be fixed, it is getting late here so I will try to follow-up on it tomorrow.
                    BTW, when you unplug the speaker connector, the squealing sound went away, that is not a good sign either. I wonder if the person also try to fix the main board.
                    Last edited by budm; 08-04-2020, 12:23 AM.
                    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

                    • storexxm
                      Senior Member
                      • Oct 2012
                      • 107
                      • Vienna

                      #30
                      Re: lg 47lx6500 backlight with sound no display

                      Originally posted by budm
                      OK, much better pictures, thanks.
                      The section that was worked on is part of LED backlights power supply.
                      I will study the power supply board further and see if it can be fixed, it is getting late here so I will try to follow-up on it tomorrow.
                      BTW, when you unplug the speaker connector, the squealing sound went away, that is not a good sign either. I wonder if the person also try to fix the main board.
                      I will resolder the ugly section with my iron...
                      yeah the squealing sound is really strange... but when i connect my ps4 and leave the tv in standby it turns on when i turn on the ps4. BUT i have to hit the input key on the remote control blind until i can hear the ps4 menu sound.
                      -> shoudnt the tv switch automatic to the right channel by itself ?
                      when i leave the tv a few minutes on the main processor cooler on the main board got really, really hot... is that normal?

                      Am i right to say there is a chip for audio output ? And that the Video Procesor maybe completely dead...?
                      Last edited by storexxm; 08-04-2020, 01:49 AM.

                      Comment

                      • storexxm
                        Senior Member
                        • Oct 2012
                        • 107
                        • Vienna

                        #31
                        Re: lg 47lx6500 backlight with sound no display

                        resoldered... nothing changed... without a scematic its hard to know if the replaced pieces were right :/

                        Comment

                        • budm
                          Badcaps Legend
                          • Feb 2010
                          • 40746
                          • USA

                          #32
                          Re: lg 47lx6500 backlight with sound no display

                          Originally posted by storexxm
                          I will resolder the ugly section with my iron...
                          yeah the squealing sound is really strange... but when i connect my ps4 and leave the tv in standby it turns on when i turn on the ps4. BUT i have to hit the input key on the remote control blind until i can hear the ps4 menu sound.
                          -> shoudnt the tv switch automatic to the right channel by itself ?
                          when i leave the tv a few minutes on the main processor cooler on the main board got really, really hot... is that normal?

                          Am i right to say there is a chip for audio output ? And that the Video Procesor maybe completely dead...?
                          Not all TV will automatically switch to the new input source when new source is connected.
                          The heatsink should not get to be too hot to touch.
                          The speakers are driven by amplifier IC.
                          As I indicated, this TV may have multiple problems so I do not know how much of your times, our times, and the money you want to spend on this TV.
                          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

                          • storexxm
                            Senior Member
                            • Oct 2012
                            • 107
                            • Vienna

                            #33
                            Re: lg 47lx6500 backlight with sound no display

                            i am going to give it away... takes too much time and place in my flat =)
                            Last edited by storexxm; 08-05-2020, 12:38 AM.

                            Comment

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