19" LCD - No Backlight - Replaced Caps - Replaced MOSFETs

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  • Braymond141
    New Member
    • Mar 2009
    • 5
    #1

    19" LCD - No Backlight - Replaced Caps - Replaced MOSFETs

    Westinghouse L1975NW 19" Widescreen LCD
    Power Supply: DAC-19M005 (DAC-19M009 Later Generation)

    I get video, but still after replacing two blown caps, no backlight. Then I replaced the mosfets, no backlight.

    As far as I can tell I'm getting no voltage to the inverter, no spike at startup, nothing. Using a craftsman digital multimeter to do the checks.

    Another member, eguevarae, mentioned SMD fuses. I'm not familiar with all the different types, but I don't see any on the board that would suggest being bad.

    Any specific things I should test? Also how exactly to test too?

    I've attached two extremely large shots of the top half and bottom half of the board. Please photoshop any test procedures or components to check You can save the images and zoom around and see far better than with the naked eye!

    ***Warning; Images are 6MBs each***

    Click thumbnail




    Thanks!
    Brett
    Tags: None
    • Braymond141
      New Member
      • Mar 2009
      • 5
      #2
      Re: 19" LCD - No Backlight - Replaced Caps - Replaced MOSFETs

      PS. I already plugged in new lamps to the board... no light up. It's not the lamps.

        Comment

        • Wizard
          Badcaps Legend
          • Mar 2008
          • 2296
          #3
          Re: 19" LCD - No Backlight - Replaced Caps - Replaced MOSFETs

          You have 3 SMD fuses, two W's and one S's. Also flip over the circuit board and give us pictures so we can see if there is other fuses.

          Must check them with ohm-meter.

          Cheers, Wizard

            Comment

            • Braymond141
              New Member
              • Mar 2009
              • 5
              #4
              Re: 19" LCD - No Backlight - Replaced Caps - Replaced MOSFETs

              Replaced one W fuse, now it just cycles through power, on off, on off. You can see the backlight quickly light up then off every time.

              Tested the other two fuses, they read just fine. The one W had a varying result.

                Comment

                • Bobdee
                  Badcaps Veteran
                  • Jun 2008
                  • 461
                  #5
                  Re: 19" LCD - No Backlight - Replaced Caps - Replaced MOSFETs

                  There is a fuse to check in the top picture , to the right edge and lower portion of picture,

                  Its black with a W on it, board number F101, [ not as big as a match head ]
                  you test for continuity

                  also can you post pictures of other side of board

                  bob

                    Comment

                    • Braymond141
                      New Member
                      • Mar 2009
                      • 5
                      #6
                      Re: 19" LCD - No Backlight - Replaced Caps - Replaced MOSFETs

                      Top

                      http://ipccomputers.org/misc/IMG_4785.jpg

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