Hey All,

I'm helping someone with their Addams Family, and I've got a weird issue that I'm not sure how to go about diagnosing. The bookcase Opto 1 will phantom trigger when the right flipper button is pressed. This happens both in switch-test and in-game. The issue is currently intermittent, but essentially game-breaking, as a player will now get points and greed letters every time they flip during a game.

I've never encountered an issue quite like this one before, and what research I've done isn't turning up a lot. But I'm leaning toward a failing or backwards diode somewhere. Which is letting back-voltage leak through to the switch matrix, which is phantom triggering the opto.

I'm going to try and follow Soren's method here, but if anyone has any ideas or knows which track I should be on, I'd appreciate the help.

Hmm, while it could be something like that, I'm skeptical it's a problem with the opto connections, since the bookcase/optos are working perfectly by themselves. The optos register exactly when they should during test and during game, so that makes me think that they're probably fine. Also, I don't see how a loose/bad opto board connection would cause the opto to close/fire when the right flipper button is pressed. But I suppose you never know. I appreciate the advice, and I'll certainly give them another look at some point.

That crossed my mind, but the thing is the opto phantom-triggers even during test when the coils aren't energized. So it's not even actually the flipper and coil itself that is triggering the opto, but simply the flipper button. As for checking the 12 v power going into the opto board, where would my test point be? I've never actually had to check power going into a board this way. Is there somewhere on the board that I can check, or would I need to pull the connector and figure out which wire was the power line?

Someone else had almost the exact same issue here: https://pinside.com/pinball/forum/topic/100-challenge-help-me-fix-my-taf

It was eventually solved by correcting the orientation of the diode on the switch that was causing phantom results. I do think this TAF problem is solvable, but at this point I think I may need to actually have this game in my workshop area. As when I was called out, I was hoping/expecting to find a misaligned or broken bookcase opto, and this is definitely something more involved. Problem is, the game is practically stuck in the guy's basement due to a narrow and steep stairway.

Came down with Covid, so haven't been back to work on the Addams Family, but I'll let you know when I do.

Feeling better now, so I went over to work on the Addams Family some more. The bookcase Opto 1 was triggering all the time today, and fluttering non-stop during switch test. Regardless of whether or not I pressed the flipper buttons. It seems like maybe the flipper button was a symptom, not a cause. So I decided to open up the bookcase itself. While doing this, I noticed that the receiver windows were very dirty. So I cleaned the opto transmitters and the receiver windows in the pf, and put the bookcase back together.

No more fluttering optos in switch test, and no more phantom bookcase/greed hits. I'm hoping the problem really was as simple as dirty opto sensors. I can't really understand how the flipper buttons were related to the problem though. My only guess would be that maybe there was a very slight voltage drop to the optos when the flipper buttons engaged, and that was maybe just enough to weaken the light beam? And since the light beam was barely making contact, even the slightest weakening of the beam would be enough to break the signal.

That's my working theory anyway. As with a lot of pinball fixes, I won't know for sure that it's fixed until the owner gets some more time on it. But I'm feeling fairly confident that I fixed the issue. But we'll see. I post an update once it's been a few weeks without recurrence.