15.1" backlight fault

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  • riget
    Senior Member
    • Sep 2011
    • 66
    • UK
    #1

    15.1" backlight fault

    Hi, got a 15.1" touchscreen monitor that the backlight only stays on for a few seconds, I've opened it and found it's a 2 ccfl, the inverter is small like a laptops, I decided to connect my meter set on 750v and found that the backlights stayed on, even with the meter turned off the backlights still worked, connecting to the other ccfl the backlights didn't stay on.
    From this I'm thinking one ccfl is weak and the meter is drawing current to make it work, is this possible? If so could I connect a capacitor between the ccfl connections and it would work?

    Thanks.
    Tags: None
    • selldoor
      Slow Learner
      • Dec 2010
      • 7870
      #2
      Re: 15.1" backlight fault

      Have you tried swapping the two lamp connectors over.
      Please upload pictures using attachment function when ask for help on the repair
      http://www.badcaps.net/forum/showthread.php?t=39740

        Comment

        • riget
          Senior Member
          • Sep 2011
          • 66
          • UK
          #3
          Re: 15.1" backlight fault

          I decided to just put another tube in it and it's working fine now.
          Strange how connecting my multimeter made it work though, and I tested it many times.

            Comment

            • tom66
              EVs Rule
              • Apr 2011
              • 32560
              • UK
              #4
              Re: 15.1" backlight fault

              Your meter is not rated for the high voltage pulse and will have likely have broken down (arced over) internally, giving the inverter the load it wants. I would not trust it further, especially on AC volts setting.
              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

                • riget
                  Senior Member
                  • Sep 2011
                  • 66
                  • UK
                  #5
                  Re: 15.1" backlight fault

                  The meter is rated to 750v, it went past this and displayed 1, so yes it wasn't rated high enough, and gave the inverter the load it needed, it also did this with the meter turned off,
                  what I wanted to know was could I introduce what the meter was doing, like adding a capacitor.
                  The meter still works fine, it must have an overload that coped with the extra volts.

                    Comment

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