The drop target that drops when the ball is plunged and later rises to lock balls stays down during play. Its up and down coils both work in solenoid test, and the subway optos register.

Lock drop target stays down in play but works in test: adjust its microswitch

Cause: The game reads a microswitch on the drop target to know its position. The switch itself was fine but the target was no longer pressing it, so the game never saw the target as down and did not call for it to raise.