This small 32.6 × 17.9 mm PCB brings separate luma (Y) and chroma (C) signals out of a Model 1 Sega Genesis / Mega Drive, giving a cleaner picture over S-Video than composite. It is made for consoles fitted with the Sony CXA1145 video encoder; Model 1 units with a Fujitsu MB3514 need a different board.

The board carries only four through-hole parts: a KSC945 transistor buffering the luma signal, a 220 µF coupling capacitor on chroma, and 75 Ω and 33 Ω output resistors. Use a plain KSC945, not the KSC945C, which has a different pinout. Wires run from the CXA1145 (pins 1, 12, 15 and 16) to the labelled pads on one side and to an S-Video jack on the other, and the board sits on Kapton tape inside the console.

This is just sharing the project from https://github.com/joshman196/Genesis-Mega-Drive-Model-1-S-Video-PCB, and all design credit goes to joshman196. The package includes the original KiCad files and Gerbers, a PCBWay BOM, and an assembly and wiring sheet.