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(Topic ID: 268357)

Segasa Monaco Ball Count/Player Count issue

By calla76759

6 months ago

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  • 4 posts
  • 2 Pinsiders participating
  • Latest reply 6 months ago by calla76759
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#1 6 months ago

Being sequestered at home, I decided to attack a long-standing problem with my Segasa Monaco. This problem has existed since I acquired it 2 years ago. I’ve treated it as a one-player machine since then, and in that configuration it works fine.

When you pick 2, 3 or 4 players, the ball count increments before the last player completes her ball. Specifically, the ball count stepper fires *not only* when the last player completes her ball, but when the *next to last player* completes her ball.

In a 2-player game, the ball count increments after every ball for every player.

In a 3-player game, the ball count increments at the end of player 2’s ball *and* at the end of player 3’s ball. By the time player 1 steps back to the machine, she’s on ball 3.

In a 4-player game, the ball count increments at the end of player 3’s ball *and* at the end of player 4’s ball.

I have putzed around with this problem a little bit. I first thought that the coin unit might be straddling two player positions, permitting conductivity across more than one of the current paths between the coin unit and the player unit. I checked that by ohming out the R-W wire with each of the wires BLU-R, R-Y and R-G (which I understand to correspond to the 1-player, 2-player, and 3-player scenarios. Confirmed that for each position of the coin stepper, only one (the correct one) of those wires has continuity with the R-W wire. So I seem to have ruled that out. And, by inspection, the coin unit is well-centered so that the stepper appears to touch only one position at a time.

I then thought that the player unit could be straddling positions. I checked that in a similar way: ohmed out the BLU-R wire that goes to the “A” position on the player unit against the R-Y, R-G, and R-W wires (B, C, and D) which I understand correspond to players 2, 3 and 4. Again, everything seems to track correctly as I move the player unit- in the player 1 position, none of the other three wires has continuity with BLU-R. For each subsequent position, only the wire associated with that player has continuity with BLU-R. And by inspection, the player unit appears well-centered so that snowshoes are dead-center on the contacts they're touching.

So, my initial hypotheses have come back dry. That doesn’t mean there’s not something wrong with the coin or player unit- just that I can’t find it.

My subsequent hypotheses start to get weird. Perhaps there’s a timing issue with the stepper motor, where the impulse 1-B comes too early or too late, and straddles two player positions. But an inspection of the score motor shows that the 1 wheel and the 2 wheel (which furnishes the impulse to the player unit, 2-B) appear to be separated by a reasonable factoryish margin.

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#2 6 months ago

Excellent work so far. Keep going. A few things I would try:

- Confirm that the Ball Count Step Up solenoid only gets pulses coming through the Score Motor 1B switch by blocking that switch with paper. The Ball Count should never advance with that switch blocked. If it does pulses are coming in through a short somewhere.

- Expand your resistance tests to include the Player and Coin Units together. Clip in to the blue-red wire leading into the Player Unit and the red-white wire coming out of the Coin Unit. Confirm that there is only a path through both units in the expected positions (Player Unit in any position and Coin Unit in position 1, Player Unit in position 2 and Coin Unit in position 2, Player Unit in position 3 and Coin Unit in position 3, Player Unit in position 4 and Coin Unit in any position).

- Figure out why your Player Reset relay isn't firing (or why the Player Unit isn't resetting) when the Ball Count advances. Each time the Ball Count advances the Player Unit should reset to player 1. The Player Reset relay is the 2nd coil down from the Ball Count Step Up solenoid.

BTW, this is essentially a Williams design. Compare the Ball Count circuit for example against Williams Big Deal made at about the same time (


#3 6 months ago

Thanks Mark. I will try your suggestions and report back!

#4 6 months ago

I blocked switch 1B with a piece of paper, and started a 4-player game. The player unit stepped correctly through players 1, 2, 3, and 4 without the ball count advancing past ball 1. So far, so good. After I played player 4’s ball 1, the player unit did not reset to player 1. I was stuck at player 4 ball 1, over and over.

This is in contrast to the machine’s normal behavior, where it is at ball 3 by the time it makes its first reset to player 1. I guess that means there’s no short that’s injecting stray pulses into the ball count unit.

I then monitored continuity between the blue-red wire from the player unit and the red-white wire from the coin unit. I stepped the coin unit to 4 players. I only observed continuity when I stepped the player unit to player 4. BUT I noticed once I got to player 4, the continuity was kinda marginal and cut off if I wiggled the pogo wheel of the player unit. Interesting, although it doesn’t explain the ball unit stepping up prematurely on player 3 (at least I don’t think it does).

I returned to my theory that there was some kind of timing problem with the score motor. I watched wheel 1 turning and filmed it with my phone. Sure enough, switch 1B was marginal and only narrowly breaking contact - very different from how its neighbor switches were gapped. I tweaked that switch and voila- the problem went away. I think the switch was making contact for a prolonged period beyond what’s prescribed by the score wheel indentation. Perhaps that caused a marginality where, as the machine was switching from Player 3 to Player 4, an improperly prolonged and overlapping pulse from 1B allowed the ball unit to increment.


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