Have you tried testing the switches in switch test? I'd get a look at the switch matrix chart in the manual and verify that all the switches are working properly. If you find one or more non working switches, verify that the wiring and diode is hooked up properly. It's possible you'll find a broken off wire or diode leg. I usually give a light tug on the wiring and diode to be sure they're firmly connected.

A problem similar to this has been posted on this forum before. Double check the switch wire colors and location. I am fairly sure the manual has this information listed incorrectly. Use the game diagnostics to figure out what is actually correct. You can determine switch state from test 07 - switch edges.

Note that lock #1 is the LOWER lock as it locks first despite what the manual location shows. Lock #2 is the upper lock as it locks second. There is no switch for the third ball when it locks. The game knows that the three balls are there based on lock #2 and the third ball passing through the second ramp diversion and subsequent switch.

01_switch_locations.jpg02_switch_wire_colors.jpg

Ran into the same exact problem 2 years ago. I just had to adjust the leaf on the Ball Lock 2 micro-switch to fix the problem.

Correct! The wire is welded onto the leaf. I just adjusted the leaf (not the wire), so it could consistently click the little button on the microswitch.