I am working on a 1969 Williams Miss-O and I’m trying to figure out why the “A”, “B”, “C”, “D” lights don’t reset between games. I am in 3 ball mode and do have the schematic. Not sure if it’s related, but the extra ball feature doesn’t seem to work correctly either. The extra ball relay comes on but it drops out before the ball reaches the out hole.

This is not the first pinball machine I’ve worked on, but this detail has me stumped. The manual doesn’t go to this level of depth.

Any help on how the game should work is appreciated. Feel free to ding me if I’ve screwed up any of the forum guidelines I’m comfortable soldering, using test tools, following schematics, and jumpering.

Thanks!

Dave

Yes, I read that too. I tested that by trigerring A, B, C, D, and rolling the ball through the horseshoe, lighting the 2 horseshoe lights. When the ball exits one of the scoring outlines, the horseshoe lights go off before the ball hits the out hole and the ball count increments. Thus the mystery

Thanks to all for digging into this and taking the time to post annotated diagrams.

I am still working through checking the switch contacts, mostly because my horseshoe is not consistently tallying the 500 points on the score reel. That looks straightforward.

Between what I studied before and your pointers, I’m starting to formulate a theory that this is the expected behavior.

1. Rolf pointed out that the A, B, C, D reset handling is different for 3 vs 5 ball games. Since game over isn’t going to drop power, they aren’t going to reset. I guess this is like a slot machine where you’ll benefit from the previous guys effort.

2. The game manual doesn’t describe the extra ball, only the IPDB entry. There is no physical trough switch on the path from the out hole to the shooter lane. I think the schematic is referring to all of the scoring lanes as trough switches. I say this because they all toggle the 100 point relay which disengages the extra ball via switch 2B, as described in the manual. I have done a test to see that if the ball sneaks out to the outhole (say under a flipper) it will give you the extra ball and clear a,b,c,d.

I am going to verify the rest of the switches that were mentioned to make sure I didn’t miss anything. Worst case, this info might help another pinsider in the future.

500 point issue fixed. Needed an adjustment of the EOS switch on the 100 point unit.

I also solved the mystery of my point #2 above. Looks like operator error on my part. The ball index relay should not be clearing my extra ball relay because it already should have come on when the ball hits one of the 100 point rollovers at the top of the Playfield. I was triggering everything by hand and neglected to follow the path of the ball. Once I did this correctly, tagged a,b,c,d and went through the horseshoe, I was able to successfully get an extra ball no matter how I got to the outhole.

So I am good. Thanks again for all the input. Hope to return the favor.

Dave

Thanks Rolf.

Looks like they had a bunch of different methods to accomplish the extra ball clearing. I think if I was going to make a modification, I’d change the wire that goes from the a,b,c,d relays to the 3/5 ball plug so that it’s always in 5 ball mode. Fortunately, my wife an I prefer it in 5 ball mode, so it all works out. This machine had a lot of glitches, so I wanted to make sure it was working as designed before I even thought about moving the Jones plug.

At this point I’m down to much more minor things like getting a credit on a match and deciding if the pop bumpers are too weak.

Thanks,
Dave