Quoted from hank35:
Here's a follow up to this fix. About a week ago, balls were hitting the upper left flipper every 8-10 launches.
Manual and auto plunges produced the same results.
Prior to this happening, all plunges were working 100%
I cleaned the playfield with Novus 1 and the balls now hit the post below the upper left flipper. I waxed the playfield and the game returned to 100%.
I would say this happened in as few as 50-75 games.
So. Before making any adjustments, clean and wax the playfield.
Lockdown bars and wax aren't solutions to the shooter lane failures. I get you've worked hard on finding a solution, but no other machine I've ever owned behaved this way. Sure, it's great to attach your lockdown and wax your PF, however shot failures shouldn't depend on pristine, waxed PF's. All it tells me is the solution you've arrived at is on the hairy edge of workable and when other variables change, shots start failing again.
The shooter lane guide is flawed...on some installations the angle is causing it to fail more than other installations. Getting the angle "just right" is really tricky, but once it's right, it shouldn't be effected by minor dirt (in a HUO environment, where it's not being played 1000 times per week).
So while it's great your game is working well again, keeping it waxed isn't a general solution for the shooter lane failures many of us have dealt with.