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Neo Geo CD

Started by kripp, December 29, 2005, 03:01:32 PM

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kripp

I've got a Japanese Neo Geo CD top loading console and it was giving me problems in the RGB department.

I read something about European consoles having to supply the sync line with a bit of positive voltage to get it into RGB mode, without the voltage it (the sync line) stays in composite mode. Thats what I understood from the information I was reading any ways. If that much is true, is it the same for the Japanese consoles?

For my console I used the pinout information from the GameSX page, I wired up my cable pin for pin. All worked just as it should but the sync line, could not get a stable image on my monitor. I opened up the console and found the CXA 1645 encoder, wired a line to the sync output and then to my monitor, sure as shit it works fine.

What I did for a permanent solution was run a wire from the CXA 1645 to the appropriate lead on the backside of the DIN connector, thinking that this would pass the sync signal to the DIN connector. Tried a test run with this configuration and it did dick all, no sync. I had to remove the A/V PCB from the console and de-solder the the connection between the sync pin on the DIN and the PCB. Now the sync pin on the DIN connector gets its signal straight from pin 10 on the CXA 1645, works great!

Any insight into this would be appreciated.

Thanks

NFG

The Neo's DIN port has both Sync and Composite Video.  Most SCART TVs can handle both, and many work better with composite video (So I've heard).

The Sync from the CXA1645 should run through a capcitor and resistor inside the NCD, as far as I remember, it's possible this is messing up your TV.  I would find this odd though.

If you have a TV/monitor, try using composite video.

As for 'adding voltage', you have to add ~1V for RGB mode in many SCART TVs, as you can see here:

http://gamesx.com/wiki/doku.php?id=av:scart_connector