Check the goofy ribbon cable that runs from the daughter board to the main board. It's pretty stiff and easily damaged. I think I still have a copy of the hand drawn sheet (there wasn't a manual per se, just some loose sheets).
I had the ribbon cable break and it didn't take to being repaired so I tried to install an ER sound commander. I get prime mover sounds but no command sounds. If I switch to conventional I get the whistle and bell sounds. The UCUB Railsounds board was meant to sit on the bed of nails connectors near the middle of the UCUB and it was never documented what the six pins did? They were definitely used for power but that would only account for two pins, what were the other four used for? There was also four wire jumper that went from the command port on the UCUB back to the daughter board. That brings the total wiring points to nine (assuming the four wire ribbon cable only uses three of the four wires).
