AOC 22LVWk only turns on with 3 lamps connected

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  • budm
    Badcaps Legend
    • Feb 2010
    • 40746
    • USA

    #21
    Re: AOC 22LVWk only turns on with 3 lamps connected

    From what I see on this power/inverter board, the power supply is an always on power supply, it runs the minute you plug it into an AC outlet, so I do not think it has PS_ON signal, it does have BL_ON (Backlights ON) signal from main board which must be working since the lamps did flash on.
    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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    • momaka
      master hoarder
      • May 2008
      • 12170
      • Bulgaria

      #22
      Re: AOC 22LVWk only turns on with 3 lamps connected

      Originally posted by budm
      From what I see on this power/inverter board, the power supply is an always on power supply, it runs the minute you plug it into an AC outlet, so I do not think it has PS_ON signal, it does have BL_ON (Backlights ON) signal from main board which must be working since the lamps did flash on.
      Indeed.

      Using the provided pictures, this is what I have decoded so far...
      Using this picture as a reference:
      https://www.badcaps.net/forum/attach...5&d=1348431519
      find the connector with the colored wires on the right. Let's call the red wire on one end Pin 1, the blue wire next to it Pin 2, and so on.
      Then you have the following pinout:
      Pin 1: ground
      Pin 2: 5V
      Pin 3: ground
      Pin 4: ground
      Pin 5: 5V
      Pin 6: 5V
      Pin 7: backlight ON signal or backlight dim signal
      Pin 8: backlight ON signal or backlight dim signal (if Pin 7 above is one of these, then this pin is the other thing).
      Pin 9: unused??

      Now, as far as the original problem, I'm not exactly sure what could be wrong.

      Do the following test:
      Hook the monitor to a computer and turn ON the computer.
      Does the power LED on the monitor stay ON when you turn the monitor ON with 4 CCFLs? What about when you have 3 CCFLs?

      If it doesn't stay ON with both 3 and 4 CCFLs, remove jumper wires L901 and L902. They are located next to those 4 Nichicon caps. Then try powering the monitor ON when it's connected to a running computer. It should stay turned ON this time. Jumper wires L901 and L902 remove power from the inverter, so if there is a fault, it wouldn't affect the rest of the monitor. You just won't get any backlight at all.
      Last edited by momaka; 09-26-2012, 08:46 PM.

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