Changing a CRT to a flatscreen

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  • #190359
    Itchigo
    Participant
      @itchigo

      I’m finally changing the old CRT in my Williams Defender to a flatscreen. The screen has been on it’s last legs for like 20 years, it needs a rebuild. I have the old tube tv out, and the flatscreen in and mounted. I am using this converter to go from the 6 wire plug to the old monitor to the converter. So I’m swapping an Electrohome G07 monitor for a Goldfinger flatscreen. (My dad is an operator and gave me the flatscreen which was designed just for this, it’s not for a computer).

      The only inputs on the monitor are HDMI, DVI, and VGA (I am using VGA).

      I am using a GBS 8200 converter board.

      Power to my board is a 5v 4a power supply (only 2a required, and I have also tried a second power supply, also 4a). The monitor is powered from the old CRT power wires.

      That leaves me 6 wires to worry about.

      Red to Red

      Green to Green

      Blue to Blue

      Ground to Ground            (I am 99.9% sure these are right!!)

      VS to VS

      HS to S (Signal?)

      There is no HS connection on the board, only a blank space. The next space over is “S”, that’s why I have my HS connected there. I have also tried moving the connection from S to the empty space of HS, making it HS to HS.

      Watch very closely at :20. This is what I get when I turn it on. Has anyone run into this before?

      Be a Rogue! http://roguepinball.com/ Full Screen DirectB2s Tables no one else has!

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      #190364
      Itchigo
      Participant
        @itchigo

        Here’s the GBS 8200 board I’m using.

        Be a Rogue! http://roguepinball.com/ Full Screen DirectB2s Tables no one else has!

        Attachments:

        Be a Rogue! http://roguepinball.com/ Full Screen DirectB2s Tables no one else has!

        #197960
        Diguelo
        Participant
          @diguelo

          A couple of things you need to be made aware of in this and other Arcade cabs.

          The old CRT screens, although functional and weighing a tons had a device on board called a LOPTi Line output transformer that handled the frame voltage and scatter magnets on the tube, all driven by a frame chip arrangemnet on the motherboard. A straight forward one to one swap isnt likely to produce a result your looking for. The frame looks like its falling out of sync by the way its collapsing off to one corner after bootup. This was a regular chip issue in CRT monitors and TV sets back in the dim and distant past.

          Ive had a scout through on Youtube and there are a few people on there that have made this modification to their machines, Asteroids, Gorf, etc and suceeded with a modification setup. Usually the power supply board rund the logic and the screen input used to be like trying to make a VGA socket output drive a DVI plug, unless you know the Pin outs, the voltages, syncs etc all I can say is put on a blindfold.

          Recommendation get the circuit diagram for the boards as they exist now and the controls etc, most systems today run on a 5V supply some of the older games had 12V.

          Getting the V sync and Hsync to tally together is going to be a problem and there should be an interface available to do this but just posting a picture of a board doesnt provide the information needed.

          As for the frame drop thats a definate chip issue. Sorry but its a case of scour “Youtube” and avoid the cat videos at all costs or itll take months. Search Repairing asteroids machine as a start.

          Ill look up any info and post it here for you.

          Silver ball go that way, as eyes went this way, GAME OVER !!

          Silver ball go that way, as eyes went this way, GAME OVER !!

          #197997
          Itchigo
          Participant
            @itchigo

            I somewhat got it going. I consulted one of my dad’s friends who is an expert in the industry. It doesn’t flicker anymore, but it is dim. It may be a matter of adjustment now, but I haven’t worked on it anymore.  I guess if it frustrates me too much I’ll find an old tv and throw it in. :)

            It’s funny, when I was an operator I always shyed away from tv repair. Now I don’t know what I was so afraid of.

            Be a Rogue! http://roguepinball.com/ Full Screen DirectB2s Tables no one else has!

            Be a Rogue! http://roguepinball.com/ Full Screen DirectB2s Tables no one else has!

            #199832
            Diguelo
            Participant
              @diguelo

              So basically then you tore out a CRT based video display and hot wired in a flat screen that had a frame collapse. Now it works but is dim.

              And all this with no consultation of circuit diagrams, voltage tables and stuff.

              Truely amazing, very well done.

              Silver ball go that way, as eyes went this way, GAME OVER !!

              Silver ball go that way, as eyes went this way, GAME OVER !!

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