Checkerboard noise on XRGB-3

[Auction_Sniper]

I have been using an XRGB-3 for almost a year now, and the quality is fantastic on Saturn RGB21 input.

Bought a Neo Geo AES a few weeks ago (Rev 3-6 with traces cut to remove jailbars) - it looks clean through composite, but there is colour noise through RGB - A weird horizontally scrolling checkboard effect appears through some colours (Green life bars, and the big blue SNK logo in Samurai Shodown II).

The Neo is hooked up through an eBay bought Scart cable > to a RGB21 adapter. Is it a fault of the cabling or the console?

[Fudoh]

On a CRT those patterns were caused by using composite video as RGB sync. On the later AES revisions both the sync and the composite video pin on the AV port actually deliver composite video. You have to make sure that the original sync signal is restored (probably by reconnecting the source to the AV port without going through the video encoder) and the RGB cable you're using is configured to use it.

I'm pretty sure that this will get rid of the patterns through the XRGB as well.

[Auction_Sniper]

Is it a matter of cutting the composite sync line on the av din input and then soldering to a pure sync line? Or will I need to do the big RGB bypass mod that requires cutting out some capacitors?

[Fudoh]

Just sync to the AV port should be fine, but depending on the condition of the raw sync signal, you might have to buffer the signal. I'm sure you'll find easy help on this on the neo-geo.com boards.