Samsung LN40B550K1F no power

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  • PeteTait
    Newer Member
    • Jan 2014
    • 41
    • United States

    #1

    Samsung LN40B550K1F no power

    I acquired this tv with out any knowledge of what the problem was. I plugged in and had no power. Opened it up checked the caps and fuses. Caps looked good. First fuse closes to power plug was good. Second fuse was blown. I swapped it and it plugged the set in and it immediately blew. Where do i look next?? attached is a picture of the board with the fuse that is blown circled in red.
    Attached Files
  • maxvalutech
    Badcaps Veteran
    • Dec 2014
    • 804
    • australia

    #2
    Re: Samsung LN40B550K1F no power

    I'll supply this circuit diagram and hopefully the real experts will chime in for you.
    Attached Files

    Comment

    • tvtimmy
      Badcaps Legend
      • Mar 2015
      • 1160
      • usa

      #3
      Re: Samsung LN40B550K1F no power

      Check these parts first. I like the Rod Farva icon. Only 9 days till supertroopers 2!
      Attached Files
      Last edited by tvtimmy; 04-11-2018, 05:32 AM. Reason: More info

      Comment

      • PeteTait
        Newer Member
        • Jan 2014
        • 41
        • United States

        #4
        Re: Samsung LN40B550K1F no power

        Well i am going to print the circuit diagram and start circling the part numbers that were recommended to check. Then find them on the board and check.

        Comment

        • freakaftr8
          Badcaps Legend
          • Oct 2012
          • 3743
          • USA

          #5
          Re: Samsung LN40B550K1F no power

          Most likely QP801 and 802S shorted. Shoddy soldering casused this most likely. Thanks ROHS lead free solder!
          Did I leave the soldering iron on?

          Comment

          • nomoresonys
            Badcaps Legend
            • Jan 2013
            • 12129
            • U.S.

            #6
            Re: Samsung LN40B550K1F no power

            Check your diodes and transistors too, see if any are bad. Testing video https://www.youtube.com/watch?v=i4jTHhXuKLA

            Comment

            • neilc6
              Badcaps Legend
              • Nov 2015
              • 1550
              • Canada

              #7
              Re: Samsung LN40B550K1F no power

              +1 for shorted transistors. See my post here https://www.badcaps.net/forum/showthread.php?t=67743

              Comment

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