Sega CDX S-Video Modification pics
Lawrence from www.gamesx.com once said that:
"This tiny well-constructed beast hates people and taking it apart is a real pain in the ass."
And you know what, he was right.
Once you manage to get the damn thing apart, it looks kinda like this:

See that space on the right where I put the RCA and S-Video ports? Yeah, that WAS the battery compartment. And that's the only real estate available anywhere in this thing. That's it. It's about 0.5 inches wide in there and you can't even use the full depth of it because the power board fits there too (it's removed in this pic, and it ain't small folks). You'll notice one of the two S-Video circuits in the upper right corner of the picture. See how small it is? It took me a bit of time to figure out the most compact way of making that so I can fit TWO of them in the remaining space you see here. Not only that, but you obviously have to solder it to the video encoder on the board (which you can't see in this pic since it's between the boards here).
Pain. In. The. Butt.
I was greatly helped out by a member of GameSX, Segasonicfan. He provided me with this FAQ.
But, once you get through it, the image quality is MUCH better, as seen on the previous page. Definitely definitely DEFINITELY worth the price of admission.
