I'm hoping someone has some guidance on how I could troubleshoot this scrambled signal from an SNES Jr. (mini) that I attempted to upgrade with an RGB bypass board using Borti4938's design... The S-Video signal is scrambled as you can see from the screencap (on a tested/working CRT). Pictures of my (admittedly amateur) soldering work on the board included...
It looks like the chroma wire on the encoder is touching pin 11 which is ground. Try repositioning it so it's not touching anything else. I'd also add more solder to all your joints and it helps to use flux as well.
I couldn't tell you whether it was a bridged pin or just piss-poor connections, but I re-worked all the wires (and the Multi-out pins for good measure), and the mod works! Beautiful S-Video is restored! Thanks!