(Topic ID: 149888)

Duotron not scoring bonus

By osudrummer

8 years ago

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#1 8 years ago

Carry over from my previous thread, none of the 500 point or bonus switches score anything. The reset coil on the bonus stepper works during startup but cannot activate the other coil that advances the bonus. I have the schematic.

#2 8 years ago





#3 8 years ago

See where it says "Add Bonus Unit" there on the left? From there, read left to right and you'll see there are three paths to it that can activate. For any one of those paths to work, the normally open switch in the path needs to close. The path through I or G also require score motor switch at 3C to be closed. And if it's on 5-ball play, the path through D and E skips down to run through two more score motor switches. There's probably a bit more to the right not shown in your picture.

So what you'll need to do is check each of those paths. So for example, does the 'I' relay activate? When it activates, does score motor switch 3C close? Same for the 'G' relay, etc.

You just have to investigate each path. Looks like it might be a bit simpler set to 3-ball mode too.

#4 8 years ago

So if I activate the I relay then the score motor should turn a little which temporarily closes 3C?

#5 8 years ago
Quoted from osudrummer:

So if I activate the I relay then the score motor should turn a little which temporarily closes 3C?

Possibly. That portion of the schematic doesn't show what causes the score motor to run. Look on your schematic for an 'M' inside a circle, then read left to right to see the set of switches that can cause it to run. There might be a switch on 'I' shown, or the motor could run due to some other event associated with I (or G, etc.).

#6 8 years ago

Didn't see an "M" inside a circle but checked 3C and it is cleaned and adjusted properly. I and G do make the motor turn but no 500 points and no bonus. I would think maybe the coil on the Add Bonus Unit wasnt getting power but it should still score right? Here is a bigger pic of the schematic. Not sure what else to try except pulling that coil and resoldering with a new sleeve.


#7 8 years ago

The score motor symbol is going to be located below the section you just posted, closer to the left side (so keep looking down from where the "Add Replay Unit" symbol is).

Anyway, if 500 points aren't scored, then that path is fairly simple. There on the schematic you'll see there's a normally open switch on G that feeds into the 100 point relay (M). When G energizes, it should lock on, so that switch should be closed. Following the path farther to the right and down, you'll see that a switch at score motor 1A needs to also close. This is the switch that provides the five pulses, which activate M the five times to give the 500 points.

Since you say that G does make the score motor run, then the next thing to check is that switch at score motor position 1A. That same score motor switch also happens to need to be closed to advance the Bonus Unit, so there's a good chance that switch is causing both problems.

The switch will be at level 'A' on the score motor (which is the bottom), at position 1 (which should be labeled on the score motor bracket). Look at the bottom left side of the schematic for a diagram of the score motor and the positions for reference.

So clean and gap the switch at score motor 1A and see how it does.

(It's a difficult switch to access with the score motor board in the game, so take your time, use good lighting, and avoid disturbing other score motor switches.)

#8 8 years ago

I was able to get to 1A with a flexstone. Even though it isnt meant for those larger contacts i was able to knock off some debris and now the bonus and scoring work!! Thanks so much for all your help!

#9 8 years ago

Excellent, glad that was it then. Enjoy the game.

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