what is this burnt part

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  • budm
    Badcaps Legend
    • Feb 2010
    • 40746
    • USA

    #21
    Re: what is this burnt part

    That is fine, it means the bridge or the MOSFET are not shorted out.
    The voltage is a little bit on the low side, if your AC is at 120v then the voltage on the cap should be 120 x 1.414 = 170vdc.
    So at this point, the power supply has no DC outputs at all?
    This power supply should be putting out 16vdc as shown on the label?
    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

    • CR Designs
      Badcaps Veteran
      • Dec 2012
      • 430
      • USA

      #22
      Re: what is this burnt part

      budm,
      What does this voltage tell?

      Comment

      • budm
        Badcaps Legend
        • Feb 2010
        • 40746
        • USA

        #23
        Re: what is this burnt part

        It is telling me that the bridge rectifier and the filter cap are functioning but I do not know if you are getting the 16VDC out put or not. If not, then the switching circuits are not working and will need more troubleshooting.
        By the way, you never tell us what the TV is not doing or what the power supply is not doing beside the over heated board/traces.
        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

        • CR Designs
          Badcaps Veteran
          • Dec 2012
          • 430
          • USA

          #24
          Re: what is this burnt part

          it will not power on the set is dead. Where should i check for the 16vDC out put?

          Comment

          • selldoor
            Slow Learner
            • Dec 2010
            • 7870

            #25
            Re: what is this burnt part

            In your picture bottom left corner there is a socket Two pins appear to be labelled 16v
            Are the other pins labelled. It is these 4? pins you need to test
            Please upload pictures using attachment function when ask for help on the repair
            http://www.badcaps.net/forum/showthread.php?t=39740

            Comment

            • budm
              Badcaps Legend
              • Feb 2010
              • 40746
              • USA

              #26
              Re: what is this burnt part

              The white connector with 4 pins is the 16vdc OUTPUT connector. Check the reading between the two red circles with your DC voltmeter, do not worry about the red/black probe of the meter, just get the two probes to the red circle.
              Attached Files
              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

              • CR Designs
                Badcaps Veteran
                • Dec 2012
                • 430
                • USA

                #27
                Re: what is this burnt part

                Have 16.24 volts

                Comment

                • selldoor
                  Slow Learner
                  • Dec 2010
                  • 7870

                  #28
                  Re: what is this burnt part

                  Can you reconnect to the main board and test again.
                  Please upload pictures using attachment function when ask for help on the repair
                  http://www.badcaps.net/forum/showthread.php?t=39740

                  Comment

                  • CR Designs
                    Badcaps Veteran
                    • Dec 2012
                    • 430
                    • USA

                    #29
                    Re: what is this burnt part

                    Connected to main board tested had 16.30 volts

                    Comment

                    • budm
                      Badcaps Legend
                      • Feb 2010
                      • 40746
                      • USA

                      #30
                      Re: what is this burnt part

                      Your power supply is fine, problem is some where else.
                      You need to provide good clear pictures of other the boards, there is link some where here in thsi forum on how the pictures should be.
                      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

                      • selldoor
                        Slow Learner
                        • Dec 2010
                        • 7870

                        #31
                        Re: what is this burnt part

                        I have been looking at some of the joints on the base of the boards.
                        Can you check the ones I have marked and if they look at all bad resolder them. Are the yellow ones the main cap? ( My top to bottom geography is not good)
                        Attached Files
                        Please upload pictures using attachment function when ask for help on the repair
                        http://www.badcaps.net/forum/showthread.php?t=39740

                        Comment

                        • Behemot
                          Badcaps Legend
                          • Dec 2009
                          • 4845
                          • CZ

                          #32
                          Re: what is this burnt part

                          Isn't the thermistor just overloaded, heating it too much? It can heat to much over 150 °C and operate normally. Yet the surroundings won't with this temperature
                          Last edited by Behemot; 01-03-2013, 04:20 PM.
                          Less jewellery, more gold into electrotech industry! Half of the computer problems is caused by bad contacts

                          Exclusive caps, meters and more!
                          Hardware Insights - power supply reviews and more!

                          Comment

                          • CR Designs
                            Badcaps Veteran
                            • Dec 2012
                            • 430
                            • USA

                            #33
                            Re: what is this burnt part

                            Will take more pictures of boards

                            Comment

                            • CR Designs
                              Badcaps Veteran
                              • Dec 2012
                              • 430
                              • USA

                              #34
                              Re: what is this burnt part

                              budm,

                              I turned the TV over to move to take more pictures of boards and the TV is working again. I guess the re solder of the burnt part did the job. Thank you for all your help !!

                              Comment

                              • budm
                                Badcaps Legend
                                • Feb 2010
                                • 40746
                                • USA

                                #35
                                Re: what is this burnt part

                                You did scrape off the green stuff and solder the current limiter back in place using flux as suggested, right? Glad to see that all it was, I have seen many colder joints for the current limiter, it will get worst and worst as joint resistance go up and more heat built up until the trace burnt or the solder crystallized.
                                I have Scepter TV with same problem, with good soldering re-work, TV is still running great after 3 years.
                                Last edited by budm; 01-03-2013, 07:02 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

                                • CR Designs
                                  Badcaps Veteran
                                  • Dec 2012
                                  • 430
                                  • USA

                                  #36
                                  Re: what is this burnt part

                                  Yes, I used fine steel wool to clean up the board,down to copper and re solder as you said. Thanks you were a great help !!

                                  Comment

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