Curtis LCDVD244A

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  • landyboy
    Badcaps Veteran
    • Apr 2013
    • 443
    • USA

    #1

    Curtis LCDVD244A

    Got another freebie and I think i have diagnosed the basic problem. The power board appears to test good. Symptoms are Power light comes on red and will go green when unit powers up but there is no picture. After checking the back light inverter I found the feed is as follows:
    VCC 12.10
    VCC 12.10
    EA 4.767
    Adj 0
    Ground 0 ohms
    Ground 0 Ohms
    There is no voltage at the inverter plugs feeding the back lights. I checked F1 and it is 0 ohms.

    I think I have a bad inverter board thoughts?
    Attached Files
    Last edited by landyboy; 05-20-2013, 04:44 PM.
  • landyboy
    Badcaps Veteran
    • Apr 2013
    • 443
    • USA

    #2
    Re: Curtis LCDVD244A

    Do these voltages look correct? What is the "ADJ" a reference to and does it look correct? Thanks

    Comment

    • budm
      Badcaps Legend
      • Feb 2010
      • 40746
      • USA

      #3
      Re: Curtis LCDVD244A

      ADJ (Adjust)= Backlights brightness control. 0V = Min brightness
      EA (Enable) = BL_ON = Backlights on control .
      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

      • landyboy
        Badcaps Veteran
        • Apr 2013
        • 443
        • USA

        #4
        Re: Curtis LCDVD244A

        Would the 0v indicate a problem?

        Comment

        • martyparish
          Badcaps Veteran
          • Dec 2012
          • 313
          • United States

          #5
          Re: Curtis LCDVD244A

          Is there a voltage at F1 when set is on?

          Comment

          • landyboy
            Badcaps Veteran
            • Apr 2013
            • 443
            • USA

            #6
            Re: Curtis LCDVD244A

            yes 12.10vdc

            Comment

            • landyboy
              Badcaps Veteran
              • Apr 2013
              • 443
              • USA

              #7
              Re: Curtis LCDVD244A

              I assume you mean the F1 on the inverter

              Comment

              • budm
                Badcaps Legend
                • Feb 2010
                • 40746
                • USA

                #8
                Re: Curtis LCDVD244A

                If you get 12v at both ends of the fuse, then try this, disconnect the ADJ line from the connector, then use 1K~2K resistor to feed 5V into the ADJ pin of the inverter board and see if you will get backlights.
                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

                • landyboy
                  Badcaps Veteran
                  • Apr 2013
                  • 443
                  • USA

                  #9
                  Re: Curtis LCDVD244A

                  Ok tried that but no change. I do now notice when I power on it will flash white for a split second. Also if I shine a flashlight on the screen I see images and the menu when I press the menu button.

                  Comment

                  • Clydeuk
                    Senior Member
                    • Jan 2012
                    • 193

                    #10
                    Re: Curtis LCDVD244A

                    Try the resistor trick mentioned (remove the adj wire out of the connector first). If it doesn't fire up the backlights I'd say inverter has failed. Don't try to measure the outputs, they are high voltage high frequency (around 1KV ish, more to start the lamps).

                    Comment

                    • landyboy
                      Badcaps Veteran
                      • Apr 2013
                      • 443
                      • USA

                      #11
                      Re: Curtis LCDVD244A

                      Did that with no change. Leaning towards a bad inverter...

                      Comment

                      • Clydeuk
                        Senior Member
                        • Jan 2012
                        • 193

                        #12
                        Re: Curtis LCDVD244A

                        You can get a 4 lamp universal inverter cheap, I keep one for testing, most are virtually the same, even ones that are built in to the power supply can be isolated and one of the cheapo's fitted, the trickiest part is usually mounting the board inside somewhere.

                        Comment

                        • Clydeuk
                          Senior Member
                          • Jan 2012
                          • 193

                          #13
                          Re: Curtis LCDVD244A

                          I've also pulled a couple of simple single lamp inverters out of old scanners, not used them but could be useful to test individual lamps in an assembly. Does the backlights even light for a second before going off? That could suggest a bad CCFL tube or connection (I've had both on these cheap sets)

                          Comment

                          • landyboy
                            Badcaps Veteran
                            • Apr 2013
                            • 443
                            • USA

                            #14
                            Re: Curtis LCDVD244A

                            The back lights seem to flash for a split second. I

                            Comment

                            • vinceroger69
                              Badcaps Legend
                              • Mar 2012
                              • 6714
                              • uk

                              #15
                              Re: Curtis LCDVD244A

                              https://www.badcaps.net/forum/showth...er+testing+cfl
                              http://www.ebay.com/itm/1pc-4-Lamp-B...item2ec1122f4b
                              both of these help me a lot in this situation to fault find.

                              Comment

                              • Clydeuk
                                Senior Member
                                • Jan 2012
                                • 193

                                #16
                                Re: Curtis LCDVD244A

                                Common faults on these cheap sets, capacitor failure, transformer failure, bad tube (broken), arcing connection between tube and metal shield (probably poor heatshrinking). These are some I've had anyway. If you can get a tube (from old screen, monitor, laptop etc) you can use to test each output. The inverter will need all 4 connected to stay running so do one at a time. If it's a tube fault you will know pretty quickly as with the bad one substituted it will fire up and stay on, with your loose tube lit as well. Then you have the nice part of taking the lcd assembly apart and trying to source a tube cheap enough to make repair worthwhile.

                                Comment

                                • landyboy
                                  Badcaps Veteran
                                  • Apr 2013
                                  • 443
                                  • USA

                                  #17
                                  Re: Curtis LCDVD244A

                                  Ok I may order an inverter or just put this on on the back-burner for now.

                                  Comment

                                  • Clydeuk
                                    Senior Member
                                    • Jan 2012
                                    • 193

                                    #18
                                    Re: Curtis LCDVD244A

                                    That will be a quick fix if it has failed, you may have to rearrange the input connector to match, though I've been lucky and one I got had the same pinouts. It's probably your best way at the moment unless you can get a working tube to test each output, since any failure in a lamp or connection to it will shut the drive off, pretty quickly.

                                    Comment

                                    • landyboy
                                      Badcaps Veteran
                                      • Apr 2013
                                      • 443
                                      • USA

                                      #19
                                      Re: Curtis LCDVD244A

                                      Ok got the cheap inverter and replaced it now set works fine. The pins on the generic board were exactly the same as the original board.

                                      Comment

                                      • Chickadee
                                        New Member
                                        • Nov 2013
                                        • 3
                                        • united states

                                        #20
                                        Re: Curtis LCDVD244A

                                        Hi Conduit just wanted to know where I can get a inverter board from
                                        I have the same model with the same problem.

                                        Comment

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