Just picking up the thread here, did you try switching on/off/on the game to see if it works? Mine had audio issue related to a reset circuit. I can find the thread if you want.
Actually here:
https://pinside.com/pinball/forum/topic/system-11-club?tu=plumonium#post-3601036
and here:
https://pinside.com/pinball/forum/topic/solenoid-fuses-keep-blowing-on-road-kings
P.S: I'm just sharing my experience, I know nothing.