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(Topic ID: 167279)

Gottlieb Duotron wont score 500pts or bonus correctly

By MagicMako

4 years ago

Topic Stats

  • 5 posts
  • 3 Pinsiders participating
  • Latest reply 4 years ago by CactusJack
  • No one calls this topic a favorite


Linked Games

#1 4 years ago

Hey guys, working on a Gottlieb Duotron, had all kinds of issues when i first got it, score motor was running constantly due to a stuck switch, some other features werent working properly and were fixed when I adjusted some relay switches. However now I am at an impass, the game does not score 500 points consistently, sometimes 500, sometimes only 300 or 400. Also, the bonus does not always accumulate or score properly, meaning if a switch is supposed to add bonus, sometimes it will sometimes it wont, and then the bonus that does accumulate does not score properly, for example if the game shows 10k bonus it may only score 8k at the end of the ball.

My gut feeling is that something is out of alignment with the score motor, maybe the 1A switch? I have cleaned all the switch stacks on the score motor and from what i can tell they all open and close properly when the motor turns. However I am still a relative novice when it comes to working on EM machines and would appreciate any help or advice. If any pictures or video would help I can provide that. Thanks a lot.

#2 4 years ago

dont have that pin, but would suspect if you can get 5 points consistently, the score motor is not at fault. but it cud be...
I believe there is a 500 point relay that holds the 100 point relay for 5 pulses.
it may also be in the bonus unit??
or maybe the player unit if it has one.
just a guess. but if you went through some of the relays and got some things workin, go through the rest of them, and you will prob have it all workin???

#3 4 years ago

I double checked the "500 point and add bonus unit relay" and it appears to be opening and closing fine.

I did notice something, the game will score 500pts correctly every third time, i hit a few 500 point switches and found that I would get a random number two times then it would score 500, for example 5-n-n-5-n-n-5-n-n-5 etc. This again points me to the score motor (i think) and something with the switch stacks but Im not sure what.

3 weeks later
#4 4 years ago

Still stuck on this..

#5 4 years ago

First off, do your chimes work? I ask because I want to know if, when you score 500 points, and it doesn't give you 500 points, do you hear 5 distinct strikes of the chime or does the chime count match how many 100's were added to the players score (less than 5)?

You also didn't indicate if it acts the same on player 2.

Trying to narrow down if it is a problem coming from the score motor (which generates the 5 pulse for the 100 point relay) or if it is a failure of the 100 point relay pulsing the score reel, or if it is the score reel skipping and not accurately tracking the pulses it is given.

You stated that the 500 point and add bonus relay energizes as it should. My question would be whether is holds in for a full cycle of the score motor each time or if it appears to be dropping out prematurely on some of the motor cycles? It must hold in for a full cycle each time in order to allow the 5 pulses to get to the 100 point score relay. It should not drop out until just before the score motor comes to rest. You might be able to "feel" this by leaving your finger on the relay switch ladder while watching the score motor. Not so much as to hold it down, but just enough to feel when it releases and hits your finger.

Two things to check on the score reel itself:

The end or stroke switch. This provides a hold circuit to the 100 point relay. It insures that when something energizes the 100 point relay, it holds in for a full stroke of the plunger on the score reel/drum unit. They often break one of the blades thereby eliminating the hold circuit to the score relay.

The anti-reverse blade - a silver finger that rides on the inside of the plastic score reel. This prevents the reel itself from skipping backwards when the plunger goes in to step it forwards. They often get bent when someone cleans the score reel (wiping strongly with a rag) and then it no longer engages with the ratchet teeth under the score reel spokes.

Bonus collect can be a lot more complicated. Is this a game that counts 1000 points for each phase of the score motor? (Slow collecting) or is it a game that counts down 5 bonus for each cycle of the score motor.

Since there are 3 phases of the score motor on a gottlieb, your theory about it being a mis-adjusted switch hold true if the score motor cams turn just slightly out of round causing some edges of the cams to push more or less than others as it turns.

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