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
    Tags: None
    • 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
                      • 12145
                      • 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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