Mega Drive AV Out (Sega Mega-Tech)

you can probe the cn8 connector (rgb1) for the main game screen you will get no output until a valid game is inserted, and the master system side of the circuit works to pass through the correct game slot to the mega drive this is ttl level rgbs (5v logic) when disconnected the sync and rgb pins are just below 5v, and when connected to a receiver drop to around 2 2 2 5v