technika lcd40-270, power issues?

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  • wills123
    Senior Member
    • Jan 2014
    • 72
    • england

    #1

    technika lcd40-270, power issues?

    this tv had a burnt transitor, diode and a few other bits on the psu, i ordered another psu and now i have 5v std by, press power button led turns blue and nothing else happens, i dont get any other voltages from psu for inverters or a 24v going to main board
    the psu is marked leke lkp-0p004.
    when i press the power button none of the voltages change so i wondered if its a main board issue all, the pins are marked,
    +12v =i get 0v,
    +5v = 5v
    +5v sb = 5v
    ps= 4.2v
    +5v = 5v

    if anyone knows wether one of those v is supposed to drop low to turn the 12 and 24v on? or is psu faulty? thanks for help, can post picture if required
  • Alastair E
    Chief Womble
    • Mar 2013
    • 1963
    • U.K.

    #2
    Re: technika lcd40-270, power issues?

    Try pressing the Third button down in the row, blue light should go off, then after a few seconds, set should come on....
    TELEFIX

    How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
    http://www.irf.com/technical-info/appnotes/an-1088.pdf
    PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

    Comment

    • wills123
      Senior Member
      • Jan 2014
      • 72
      • england

      #3
      Re: technika lcd40-270, power issues?

      ok tried that, no joy, when in stanby the led is red, press the button on remote or the tv and it turns blue, it does flash once each time another button is pressed, the third in the row is volume button. pressing standby again makes led turn red again, thanks

      Comment

      • Alastair E
        Chief Womble
        • Mar 2013
        • 1963
        • U.K.

        #4
        Re: technika lcd40-270, power issues?

        Worth monitoring those voltages--While you're trying to turn the set on....

        Onedmay be dropping out or going low causing it to fail to start....
        TELEFIX

        How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
        http://www.irf.com/technical-info/appnotes/an-1088.pdf
        PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

        Comment

        • wills123
          Senior Member
          • Jan 2014
          • 72
          • england

          #5
          Re: technika lcd40-270, power issues?

          sorry i should of said that i measured them whilst trying to turn on also, nothing changes between turning the set on and off,
          was what made me think maybe the main board wasnt telling the psu to switch on the 12v and 24v supplies, i think that show it should work anyway , just not sure which pin it is that is supposed to do that , thanks

          Comment

          • wills123
            Senior Member
            • Jan 2014
            • 72
            • england

            #6
            Re: technika lcd40-270, power issues?

            is there a list somewhere of what each pin label means? or is it just a matter of learning over time, i.e ps-on = power supply on.
            i tried grounding ps, also 5vstb but it dint make the psu work, so maybe i do have a faulty psu lol

            Comment

            • budm
              Badcaps Legend
              • Feb 2010
              • 40746
              • USA

              #7
              Re: technika lcd40-270, power issues?

              Good clear pictures of the board, both top and bottom may help, and around the connectors so we can see the labels.
              +12v =i get 0v,
              +5v = 5v
              +5v sb = 5v
              ps= 4.2v
              +5v = 5v

              The PS is more likely to be the PS_ON pin.
              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

              • wills123
                Senior Member
                • Jan 2014
                • 72
                • england

                #8
                Re: technika lcd40-270, power issues?

                finnaly got to the bottom of this one, the supply i recieved was faulty, ps pin is the ps-on signal and when jumpered to 5v on a working supply all voltages come up. The mainboard is also faulty on this set so maybe one board took the other out, who knows lol

                Comment

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