Anyone have hot tips on how to debug/repair the drop bank opto sensors? I took apart my bank the other day to replace the springs and clean it (was feeling real sluggish on some of the targets) and now I can't get switch detection on the second target.

I verified that the switch still engages at the header cable that plugs into the PCB, removed the coil assembly and tested by manually blocking the opto receivers. All the other four reported as expected, but number 2 gives me nothing. There's no visible damage to the board or any resistors.

Shy of replacing the whole board, what are your suggestions for finding the issue and repairing?

Thanks for the guidance! I bought some replacement optos from PBL and swapped out the troubled one, but it still doesn't register. Jumping the pins on the header cable *does* register, so it's gotta be something on the board itself. Nothing looks out of the ordinary.

What else could it be, I wonder?

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If it's got the original mylar protector it'll probably have some bubbles, and dimples on the left lane and center play field where the ball drops down—but those are pretty much inevitable for a 30+ year old game, so doubtful it'll affect your decision.

As noted above, drops are probably the most vulnerable mechanic. Optos can die so switches don't register, coils can get gunky so they don't reliably reset. But those can be readily fixed with $7 opto and a $0.75 coil sleeve, so again... probably won't affect your decision.

Really, all you need to know is whether it can LIONMAN!!

The game physically can't eject just a single ball from the lock, so if two balls get in there it has to start a multiball because they're both going to come out.

Normal "accidental" two-ball multiballs happen when one ball is locked and the next ball goes up the left lane but not far enough to hit the scoop, so it falls down into the lock. It's not common, but it certainly happens from time to time in regular play.

Bospins This shouldn't happen from the ramp though, because the game should eject the first ball before the second one arrives. This would be determined by the incoming ball hitting the switch as it crosses over the playfield—perhaps your switch is faulty? If that switch isn't detected then the first ball won't be kicked out, and the two-ball multiball rules will take effect.

It's on the game roms and you can play it directly, but it isn't used during gameplay at all.

Extra ball is the final prize of the AVENGER completions, there's a progression on the bottom that starts at 50k and goes up to Extra Ball. Or, if you have a really bad first two balls, it'll light EB when you start ball three and just complete AVENGER to collect it.