42pfl8404h/12 no backlight, sound is OK

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  • domix
    Senior Member
    • Jan 2014
    • 166
    • Slovenia

    #1

    42pfl8404h/12 no backlight, sound is OK

    Hello,
    Tv suddenly goes black, when tv was watched.
    Sound is ok, but no picture. I turn off and on, and sound is ok but ni picture.

    If i light it with flashlight very close in the screen i see picture. So backlight it not working. Is there any way to solve this, but not to buy a new board?

    Thanks
  • trunks81
    Badcaps Veteran
    • May 2020
    • 265
    • Nederland

    #2
    Re: 42pfl8404h/12 no backlight, sound is OK

    Can you post an photo of the powersupply board ?

    Comment

    • neilc6
      Badcaps Legend
      • Nov 2015
      • 1550
      • Canada

      #3
      Re: 42pfl8404h/12 no backlight, sound is OK

      90% of the time if you have no backlights on a LED TV, you have bad backlights.

      Comment

      • budm
        Badcaps Legend
        • Feb 2010
        • 40746
        • USA

        #4
        Re: 42pfl8404h/12 no backlight, sound is OK

        Show us the pictures of the back side of the TV showing all the boards, and then good clear straight shots of the whole power supply board.
        What Voltage measurement have you done so far?
        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

        • trunks81
          Badcaps Veteran
          • May 2020
          • 265
          • Nederland

          #5
          Re: 42pfl8404h/12 no backlight, sound is OK

          this isnt a led tv but an CCFL, Most common fault on these boards are the blue caps at the inverter

          Comment

          • domix
            Senior Member
            • Jan 2014
            • 166
            • Slovenia

            #6
            Re: 42pfl8404h/12 no backlight, sound is OK

            Trunks81 you have right. I found this 2 blue little buddy
            I will replace them. It is good to replace all 4 of them?
            What is the text on this broken one? I cant read it, know everyone?

            Thanks
            Attached Files

            Comment

            • domix
              Senior Member
              • Jan 2014
              • 166
              • Slovenia

              #7
              Re: 42pfl8404h/12 no backlight, sound is OK

              I found it, this is might be okey

              https://www.ebay.com/itm/Netzteil-Re...-/262485024936

              Comment

              • trunks81
                Badcaps Veteran
                • May 2020
                • 265
                • Nederland

                #8
                Re: 42pfl8404h/12 no backlight, sound is OK

                if iam not wrong it is 2x22 and 2x33 you can read the values on the side that is not broken.
                Better to replace them all. Also they are 5kv you should replace them with 6kv
                Last edited by trunks81; 09-07-2020, 12:12 AM.

                Comment

                • domix
                  Senior Member
                  • Jan 2014
                  • 166
                  • Slovenia

                  #9
                  Re: 42pfl8404h/12 no backlight, sound is OK

                  It is 33 6kv like on that ebay link.
                  I have a local store with electronic parts, they only have all this values 33pF and 22pF, but only 5KV, it is okey if i read 6KV on old ones ?

                  Comment

                  • trunks81
                    Badcaps Veteran
                    • May 2020
                    • 265
                    • Nederland

                    #10
                    Re: 42pfl8404h/12 no backlight, sound is OK

                    no you need to replace them with 6KV
                    Last edited by trunks81; 09-07-2020, 12:18 AM.

                    Comment

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