RGB problems with consolized NeoGeo MV1c

Discussion in 'Arcade and Supergun' started by erkan, Sep 7, 2013.

  1. synrgy87

    synrgy87 Well Known Member

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    this is a good shout, i use the lm1881 circuit as a sync stripper for my GBS 8220 so i can do rgb scart with composite vide as sync > vga it works nicely
     
  2. erkan

    erkan Spirited Member

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    Sorry for not posting pics before but I was burned out on this project.

    Now I have purchased a Mak Strike Supergun from Arcadeforge and picture is great with it (on the MV1-B, the MV1-C has problems).

    However, do not expect everything is working 100% yet (dont worry I am used to problems).

    I also got a Neo Geo kidney joypad since the supergun got 15 pin joystick pinouts. The joypad is in like new condition, but up or down does not work properly. In the 161 in 1 menu I can not go up or down in the menu, and in games where you can jump and duck suck as Metal slug both pushing joypad up or down makes the guy duck so I guess there is some kind of short circuit either in the joypad or the Supergun.

    Is there an easy way of testing if the joypad or supergun is broken without purchasing a second joypad?

    UPDATE:

    Found out the joypad testing screen, in 2 player connector in test mode the joypad was fully working, in 1p port up registers as up and down, and down also registers as up and down at the same time. So my Strike gun Mak ultra is broken maybe?
     
    Last edited: Jan 8, 2014
  3. Xian Xi

    Xian Xi Rising Member

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    The Neo Geo AES's CXA1145 video encoder takes raw sync directly from the LSPC/LSPC2, nothing in between. The sync output from the AV socket is from either pin 11 (sync out) on the CXA1145 or on the later models is just composite video. Before the AV socket the sync passes through a 470uf cap and 75ohm resistor for AC coupling.
     
  4. erkan

    erkan Spirited Member

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    Wow finally got everything sorted out now!

    Damn, I thought this would have been a 2 week project :)
     
  5. Bearking

    Bearking Konsolkongen

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    Just wanted to chime in on this as I'm making a cMVS. I tried both the methods, one being the RGB lines from the board > 100ohm resistors > XRGB-mini, and Calpis' suggestion like described above, but with 100uF > 100ohm resistors after the THS amp.
    There is a very small improvement in picture quality by using Calpis' method, so I'm obviously going forward and building this circuit for my cMVS. Don't add a capacitor between power and ground on the THS amp, as it will cause the picture to blur slightly.

    As far as I understand you, the Sync signal from the egde connector is just right on it's own, and requires no additional components? This obviously works fine for the XRGB-mini, but I don't have a consumer CRT handy for me to test this on. I have a Sony BVM in the basement, but I assume that will be more tolerant than a regular consumer TV.
     

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