I've been messing around with RGB modding my consoles for the past few months. I would have to say that its been, probably, the least successful venture I've ever embarked on in my entire life. Its failure at every turn.
I bought a XRGB2+ from a forum member. It arrived broken. I posted a thread saying I'd like to buy another one for a reasonable price. Another forum member offered to sell me his, but then ended up selling it to someone else for more money without even consulting me to see what I would pay. I bought a GBS 8220 to view the RGB signal on a VGA monitor. It works perfectly with MVS boards and with the Saturn I modded. All success stops there.
I pulled the RGB from a PCE and cannot get it to sync with the GBS 8220. I will sync with a Commodore 1080 monitor, but of course it is very dark. I've tried two different kinds of amps and both only manage to turn a dark signal into a non-existant signal.
I bought SNES and Genesis SCART cables, since they also use composite sync they won't work with the GBS 8220. I built a sync separator/amp circuit out of an LM1881 and it basically doesn't function. I built (or at least tried to build) the exact circuit I think other people are using with a SCART to GBS 8220, and I get the same results I'd get without the LM1881.
I tried to do exactly what this guy has done (be warned, he takes f*cking forever to get to the point) but I don't know his exact schematic:
I've never had such a problem with electronics before. I've modded...basically every system I've ever owned, on one way or another. I built the ECU running my car right now. I built Heath kits as a kid, etc. This thing though, which is really kind of simple, just shuts me down at every turn.
Part of the problem is a lack of known factors. What pins, exactly am I actually supposed to be using from the SCART socket? Its astonishingly difficult to get this info. Do I get the composite from pin 19 or 20? All SCART cables I've seen are very very poor quality, so that's an issue too. When something doesn't work (which is always) I don't know how to narrow down my list of variables. Is the cable shit? Am I using the wrong pins? Is the amp circuit built correctly? Is there a problem with all three?