Flatron W2240s power board oscilating voltage

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  • 6ot4hr
    Senior Member
    • Oct 2014
    • 87
    • Croatia
    #1

    Flatron W2240s power board oscilating voltage

    Hi, i have a problem with Flatron W2240 and tu68c8-7a power board, board should have +5.1V, +22V for logic board and inverter but my voltages jump from +2.8V to 5.2V on 5V rail, and from 21.7V to 22.5V on 22V rail when logic board is connected, and when its unpluged they oscilate +/-0.2V from nominated voltages...

    Anyhow, changing caps didn't help, so i tested for shorts and found nothing shorted. I powered the logic board with external +5V and monitor worked

    After that test Power board magically started working, and the monitor worked for 2 weeks on its own Power board with no problem, till today...

    Again, +5V rail is going from +2.8V to +5.2V
    +22V rail is going from +21.5 to +22.2V

    Logic board draws 100 to 200mA on 5V when connected to external PSU and the voltage oscilate without ccfl lamps being connected to the board

    Anyone has suggestion what to do?
    Last edited by 6ot4hr; 01-06-2018, 09:28 AM.
    Tags: None
    • budm
      Badcaps Legend
      • Feb 2010
      • 40746
      • USA
      #2
      Re: Flatron W2240s power board oscilating voltage

      We need pictures of the board.
      Did you check/replace the start-up/running cap in the primary side of the circuit?
      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

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