Lnt5271fx/xaa

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  • fxdfireman
    Senior Member
    • Nov 2010
    • 86
    • USA

    #1

    Lnt5271fx/xaa

    I got a Samsung LNT5271FX/XAA from a friend. When i got it it was dead no power, on stand by light. I looked over the boards and in my newbie thinking figured that the power supply failed and took out the main board. I ordered and replaced the power supply and main board and it worked when i turned it on. I turned it off and when i tried to turn it on again it would not do anything. Now it is like before no standby light. It does have 5V going to the main so i don't think its the power supply but what else would cause the main to go again?

    Thanks for any help!



    Attached Files
  • dick_barton
    Badcaps Legend
    • Aug 2015
    • 6642
    • Wales

    #2
    Re: Lnt5271fx/xaa

    Can you provide a list of the legends alongside the connector pins and what the voltages are?
    Attached Files
    Willing to help but I'm no expert.

    Comment

    • fxdfireman
      Senior Member
      • Nov 2010
      • 86
      • USA

      #3
      Re: Lnt5271fx/xaa

      OK Will get them after work.

      Comment

      • fxdfireman
        Senior Member
        • Nov 2010
        • 86
        • USA

        #4
        Re: Lnt5271fx/xaa

        Here are the voltages and pictures. thanks for taking a look. Sorry it took so long to get back.

        1 - 0.039
        2 - 0.039
        3 - 5.191
        4-12 - 0
        13-16 - 0.039
        17-18 - 0
        19 - 0.370
        20 - 0
        21 -0.370
        22 - 0.374
        23-24 - 0
        Attached Files

        Comment

        • budm
          Badcaps Legend
          • Feb 2010
          • 40746
          • USA

          #5
          Re: Lnt5271fx/xaa

          It would be nice if you had put the pin names for each pin.
          Right now the main board is not sending the PS-ON signal (Pin 1) to turn on the rest of the the power supplies.
          Try disconnecting the cable between the main board and the FRC board (the board between the main board and the T-CON board) to see what happen.
          May be your new board is bad too.
          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

          • fxdfireman
            Senior Member
            • Nov 2010
            • 86
            • USA

            #6
            Re: Lnt5271fx/xaa

            It seemed to work initially. I am thinking that whatever caused the first board to be bad caused the second to fail also.

            Comment

            • dick_barton
              Badcaps Legend
              • Aug 2015
              • 6642
              • Wales

              #7
              Re: Lnt5271fx/xaa

              Disconnect the power supply from the main AV baord and connect a 1K resistor between pin1 (Power On/Off) to pin 3 (STB5.2V) and check that all the other supplies come up.
              Willing to help but I'm no expert.

              Comment

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