Standby Voltage

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  • tech2014
    Badcaps Veteran
    • Aug 2014
    • 807
    • Canada

    #1

    Standby Voltage

    Isn't the standby supposed to be on when the AC is plugged in and goes into full power mode when the power button is pushed.

    I have a tv that has standby LED but the standby voltage keeps jumping around between 5v and 0.5V. Any reason why?
  • budm
    Badcaps Legend
    • Feb 2010
    • 40746
    • USA

    #2
    Re: Standby Voltage

    The standby power supply is an always on power supply which runs the minute the AC is applied.
    So if you disconnect the load from the standby, will it become steady?
    It is in the loop (shutdown/startup) right now which can be due to bad cap, too much load being applied, shorted/leaky rectifier in the secondary side, etc.
    Make/model/pictures of this unit?
    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

    • tech2014
      Badcaps Veteran
      • Aug 2014
      • 807
      • Canada

      #3
      Re: Standby Voltage

      Hi budm. Here is the link to the original thread on this tv. https://www.badcaps.net/forum/showthread.php?t=39729

      I am leaning towards the main board being the problem. When I disconnect the load there is no change. I notice that I never get a VS_ON signal which is from the main board. I tested it with load and removed each board and still no VS_ON. The 5V still goes between 0.5 and 5V no steady 5V.

      Comment

      • tom66
        EVs Rule
        • Apr 2011
        • 32560
        • UK

        #4
        Re: Standby Voltage

        When I disconnect the load there is no change
        So the standby still bounces with main board out? Could be bad start up capacitor.
        Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
        For service manual, schematic, boardview (board view), datasheet, cad - use our search.

        Comment

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