the basics: check all the harnesses that control sound, reseat any harness you removed when searching for the lack of sound issue. if the switch issues are new, probably again, just a harness issue.
pull and reseat the music sound rom(s), i don't remember which one that is. remove and reseat any sound chips, look for brittle legs.
if you start a game, and solenoids are ALL firing with no ball going into the shooter lane, it sounds like it's doing a ball search. clean/check the ball trough switches. check for a stuck ball in the right VUK, the right trap lane, etc...