Enter test mode and step to solenoid test. Let it cycle through a couple of times following along in the manual. Make sure all the correct #s are displayed for the solenoid in action.

Then go into switch test (ball out of game, all targets up) and drop the multiplier targets one at a time and make sure the correct # is displayed for them as well.

Also, the solenoids driven by the Solenoid Expander Board should have two diodes affixed to their lugs. If one-diode coils are fitted at those designations, very weird solenoid behavior ensues.