Quoted from silver_spinner:

as an owner of many sterns and work on many sterns almost daily (old and new):
1) replace the connectors that go to both trough boards (thanks parker).
2) solder everything, not just the pins on the trough boards. doesnt matter if game is new out of box, the trough boards are NOT new. I bought a NIB SEGA harley davison and the optos' solder joints to the motorcycle already were cracked and didnt work properly on game number 1 played.
3) check your weldement at top of trough kick out. if its cracked, broke/raised up, a ball can shootout and fall back in from the shooter lane, then it kicks out 2 balls because 2 balls are now in the up kicker part of trough.
*if you do all of the above and the problem Does not go go away, one or both of your trough pcb has a real problem. replace those and you are done.

Quoted from LTG:

Leaf blade, not micro mini switch.
LTG : )

Quoted from wtuttle:

Seems nobody has had this issue in some time, but I am stumped. I have a TWD Premium. It is a four-ball game with micro-switches in the ball trough. My last switch, where the fourth ball would rest if there were none in play (#18) stays lit unless the playfield is tilted in the opposite direction it's supposed to go. I've tried re-seating the connectors. I lack the ability (and tools) to re-solder.
Any ideas? It would be much appreciated. I'll donate $20 to Pinside if someone can save me from calling a tech over!
Cheers from Canada,
Winston.

Quoted from wtuttle:

Hmm, thanks for the idea. I'm going to investigate this in the morning. I just played a game with three balls (instead of the four) and now my Well Walker isn't registering hits! I feel like some gremlins got in my machine! It was maintenance-free for 10 months, but is now wonky.
Thank you all for reading. At least I don't feel alone in the battle!
-Winston.

Quoted from wtuttle:

Seems nobody has had this issue in some time, but I am stumped. I have a TWD Premium. It is a four-ball game with micro-switches in the ball trough. My last switch, where the fourth ball would rest if there were none in play (#18) stays lit unless the playfield is tilted in the opposite direction it's supposed to go. I've tried re-seating the connectors. I lack the ability (and tools) to re-solder.
Any ideas? It would be much appreciated. I'll donate $20 to Pinside if someone can save me from calling a tech over!
Cheers from Canada,
Winston.

Quoted from wtuttle:

Hmm, thanks for the idea. I'm going to investigate this in the morning. I just played a game with three balls (instead of the four) and now my Well Walker isn't registering hits! I feel like some gremlins got in my machine! It was maintenance-free for 10 months, but is now wonky.
Thank you all for reading. At least I don't feel alone in the battle!
-Winston.