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Viewsonic/DGM/Digimate Monitor flashes for 2 seconds then off!

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    Viewsonic/DGM/Digimate Monitor flashes for 2 seconds then off!

    Hey folks,

    I've got a DMG 24" monitor bought from ebay, the user said it was working fine and then it just started to show lines on the LCD.

    So I grabbed it opened it up and saw clearly two bad caps, plus a third that was the same make (and identical farad and voltage), so I replaced all three. In the process however I seem to have snapped the board that contains the buttons!

    Now the LCD just flashes on for about 1 second (all seems perfect image wise), then goes black. This happens when power cable is re-plugged and ALSO when the DVI cable is re-plugged in also.

    Since the buttons are broken a little multimeter check showed the buttons are high and each button takes the line low to trigger it.

    Since I have it disassembled, I can hear a high pitched noise when the monitor powers on, it then disappears for a few seconds (while the LCD backlight is on) and then re-appears once the panel switches goes black (and stays there), once I unplug from mains the sound seems to wind down slowly.

    So folks your help on getting this fixed would be most welcome! It's an extremely nice LCD and only reason I bought it is for sentimental reasons, I had the exact same panel a few years ago and had to sell.

    Monitor also goes by the name of Digimate, Yuraku but is acutally a Viewsonic Optiquest Q241wb.

    The full schematic is here:

    https://www.box.com/s/mtulxa4od8doiulm0du7
    Last edited by rash.m2k; 05-03-2013, 02:13 PM.

    #2
    Re: Viewsonic/DGM/Digimate Monitor flashes for 2 seconds then off!

    pictures of the power board:

    https://www.box.com/s/9r8h8nalopf5mzj2banz

    https://www.box.com/s/nhd7s48wpyy00z8e6nsf

    https://www.box.com/s/8ztl1ym5ssfbs8tqlb3n

    Comment


      #3
      Re: Viewsonic/DGM/Digimate Monitor flashes for 2 seconds then off!

      Please update your profile with country and mains voltage.
      Please re post your pictures using manage attachments - may get more members to view them - better still re take them as follows

      Test the secondary windings on each of the small transformers.

      Welcome to the forum-
      We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

      Please do not post inline and offsite as they slow down the loading of pages.

      Examples of what is needed

      https://www.badcaps.net/forum/attach...7&d=1280167246

      https://www.badcaps.net/forum/attach...6&d=1280167246

      https://www.badcaps.net/forum/attach...4&d=1280167246
      Please upload pictures using attachment function when ask for help on the repair
      http://www.badcaps.net/forum/showthread.php?t=39740

      Comment


        #4
        Re: Viewsonic/DGM/Digimate Monitor flashes for 2 seconds then off!

        Ok I'm in the UK and my mains voltage is 240v. Although I can solder I'm not a electronic engineer, but not afraid of getting stuck in with electronics.

        Whan you say 'small transformers' do you mean the black ones on the left? I have a digital multimeter so can check the voltage of these - what should it be?
        Attached Files

        Comment


          #5
          Re: Viewsonic/DGM/Digimate Monitor flashes for 2 seconds then off!

          You should check the resistance across each of those transformers are all the same. One or more that is different from the normal usually indicate a bad one.

          Comment


            #6
            Re: Viewsonic/DGM/Digimate Monitor flashes for 2 seconds then off!

            Lol folks you are not going to believe this, turns out I had bent the inverter pins. Straightened them out and all working now!!!!

            Comment


              #7
              Re: Viewsonic/DGM/Digimate Monitor flashes for 2 seconds then off!

              Originally posted by rash.m2k View Post
              Lol folks you are not going to believe this, turns out I had bent the inverter pins. Straightened them out and all working now!!!!

              What inverter pins?
              Please upload pictures using attachment function when ask for help on the repair
              http://www.badcaps.net/forum/showthread.php?t=39740

              Comment


                #8
                Re: Viewsonic/DGM/Digimate Monitor flashes for 2 seconds then off!

                Originally posted by selldoor View Post
                What inverter pins?
                On the left hand side in the first picture, the white connectors (above and below where it says ABCDE FGHIJ), the pins inside the connectors where the inverters plug in were bent - so one pin would make contact and not the other, so a complete circuit would not be made.

                I straightened the pins and voila! Working!

                Comment


                  #9
                  Re: Viewsonic/DGM/Digimate Monitor flashes for 2 seconds then off!

                  Thanks - those are the lamp sockets.
                  Something else for us to look out for
                  It is usually the lamps or the transformers, we tend to overlook the
                  connector.
                  Please upload pictures using attachment function when ask for help on the repair
                  http://www.badcaps.net/forum/showthread.php?t=39740

                  Comment

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