The second generation Bally sound board does not have an elaborate test sequence. I'm not sure why there is a button on the board. Fortunately it has been remade by a few vendors so if worse comes to worse it can be replaced.
Things to try include:
*Crank the volume controls back and forth a few times to clean them internally
*Order a cap kit and replace the large caps
*reflow the solder to the connector pins.
*Check the speaker and wiring.

We used to have 2 rules:
1. No problem is as difficult as it seems
2. No problem is as easy as it seems.
3. Start with rule 1 then go on to 2.

OK that's 3 rules, my bad.

Yep, Bob Chins is about a 10 minute drive for me. However I spend more money at the Superdog that opened next door.