If you're buying a sound board, did you ever see my Type 1 Sound board? Completely re-engineered hardware and software running on modern chips. Integrated diagnostics built in to the board so it tells you if an input line is shorted or never used (open circuit).
-Rob
-visit https://www.kahr.us to get my daughterboard that helps fix WPC pinball resets or my re-engineered Type 1 sound board for classic Williams games