Bad power supply 40 coby

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  • dbraffo
    Member
    • Dec 2013
    • 22
    • usa

    #1

    Bad power supply 40 coby

    Hello all. Have a strange one here. I fixed a 40 Coby about 8 mo ago and the other day heard a pop no picture standby light no nothing. Pulled back off very hot inside could not find any blow or Bad caps. I did replace a few on the first fix. The 3.3 mosfet was the problem before so I checked it, was putting out 2.95 volts so I replaced it as I had some spares. That wasn't it. Doing some checking on the power supply it is powered up all voltages are there but you turn it off, at all stuck on. Unplugged the led from mother board no change. Power supply only have 5v on stby as it should. Plug it back up to main board all voltages there and correct except PSON and it has 2.95v.
    On clicking of course of relay on power board because it is on. Any thoughts would be great. AB
  • budm
    Badcaps Legend
    • Feb 2010
    • 40746
    • USA

    #2
    Re: Bad power supply 40 coby

    You can start with this:
    https://www.badcaps.net/forum/showthread.php?t=39740
    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

    • dbraffo
      Member
      • Dec 2013
      • 22
      • usa

      #3
      Re: Bad power supply 40 coby

      Maybe this will help
      Attached Files

      Comment

      • ReeceyBurger123
        Never Give Up !
        • May 2014
        • 7325
        • Britain

        #4
        Re: Bad power supply 40 coby

        We need photos of the boards as well.
        Please Do Not PM My Page Asking For Help Badcaps Is The Place For Advise, Page Linked For Business Reasons Only. Anyone Doing So Will Be Banned Instantly !

        https://www.facebook.com/Telford-Tel...7894576335359/

        Comment

        • dbraffo
          Member
          • Dec 2013
          • 22
          • usa

          #5
          Re: Bad power supply 40 coby

          Sorry one at a time
          Attached Files

          Comment

          • dbraffo
            Member
            • Dec 2013
            • 22
            • usa

            #6
            Re: Bad power supply 40 coby

            Power board
            Attached Files

            Comment

            • dbraffo
              Member
              • Dec 2013
              • 22
              • usa

              #7
              Re: Bad power supply 40 coby

              Sorry for one pic at a time, new up date on iPad causing havoc

              Comment

              • budm
                Badcaps Legend
                • Feb 2010
                • 40746
                • USA

                #8
                Re: Bad power supply 40 coby

                Sorry but the pictures quality is very poor.
                What is this TV model number? May be I can find better pictures at shopjimmy .com
                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

                • dbraffo
                  Member
                  • Dec 2013
                  • 22
                  • usa

                  #9
                  Re: Bad power supply 40 coby

                  Coby tftv 4025 power board is appc220p-4a
                  Thanks I'll try my android to reload pics

                  Comment

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