42PFL7422D LG Inverter Modification II v1.2

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  • electrodog
    Member
    • Jul 2012
    • 19
    • USA
    #1

    42PFL7422D LG Inverter Modification II v1.2

    I want to install the inverter board mod, but looking at the LG inverter mod II v1.2 pdf, It doesn't seem clear which way to install the zener diodes. Can anyone tell me, are they showing that there is a polarity mark on the board at the pads to install the zeners? I don't want to do it wrong and install them backwards.

    Thanks,

    electrodog
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    • budm
      Badcaps Legend
      • Feb 2010
      • 40746
      • USA
      #2
      Re: 42PFL7422D LG Inverter Modification II v1.2

      The 33V Zener Diode is connected between B+ (24V) and Ground on the board, the Band on the Diode will be connected to the Positive and the other end will be connected to ground. Just post the pictures so I can redline them for you.
      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

        • mockingbird
          Badcaps Legend
          • Dec 2008
          • 5484
          • -
          #3
          Re: 42PFL7422D LG Inverter Modification II v1.2

          May I ask about the origin and purpose of this modification?

            Comment

            • budm
              Badcaps Legend
              • Feb 2010
              • 40746
              • USA
              #4
              Re: 42PFL7422D LG Inverter Modification II v1.2

              LG/Philips released the first MOD which still did not fix the blown up IC and MOSFETs on the inverter boards, so they released the II fix, only time will tell if it will truly fix the problem.
              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

                • electrodog
                  Member
                  • Jul 2012
                  • 19
                  • USA
                  #5
                  Re: 42PFL7422D LG Inverter Modification II v1.2

                  budm,

                  If you look at the inverter mod II document SCC_73709 page 13, you'll see arrows pointing to the pads. Are the arrows where the anode gets placed on the pads? They describe: Polarity: band mark position and non polarity: no placing direction. Should I solder the anodes to the pads where the arrows point? I just want to make sure since I don't have a schematic.

                  Thanks,

                  electrodog

                    Comment

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