(Topic ID: 259236)

1975 Chicago Coin Top Machine Help (With a schematic!)


By Gnrwarkfc

39 days ago



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  • 33 posts
  • 5 Pinsiders participating
  • Latest reply 38 days ago by Mopar
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#1 39 days ago

Hello everyone! Firstly thanks so much to anyone who's already helped me on this machine prior. I'm brand new to EM pinball and I can't tell you the confidence you folks have already given me to fixing my own machine. Without your help I wouldn't be as far as I am already. Thanks so much.

I have several issues that have occurred in my game and I was curious if anyone could offer a suggestion.

1) (and I think I'll just start here because it's the most annoying) I have a loud buzzing sound that continues throughout all play of the game. I'm not entirely where the buzz is coming from but it's not like a hum or electrical sound. It's a purposeful buzz that typically in the game just sounds (I believe) when the ball rolls over the two rollover targets that changes points to 100 to 1,000 points during game play.

2) My game typically upon starting a game with kick out the first ball but will fail to kick out the next ball for the next game.

Here's my schematic. https://images.pinside.com/f/11/b5/f11b5fb1e63f1b7998e72535a1b7bad9d162ef9c.pdf

I'm super knew to this but I do have a deep desire to learn how to work on em machines.

Thanks so much for any information anyone could provide. How do I stop this sound!!

#2 39 days ago

Can you look inside and see exactly where the buzzing sound is coming from?

#3 39 days ago

You'll need to stick your head in and track down the buzz, then: http://www.pinrepair.com/em/index3.htm#buzz

#4 39 days ago

Thanks so much for this tip! I’ll do right when I get home.

#5 39 days ago
Quoted from Gnrwarkfc:

(I believe) when the ball rolls over the two rollover targets that changes points to 100 to 1,000 points during game play.

Hey, good timing with the ears.
From your statement here, it sounds like the buzzing is coming from something like an alternative relay.
The Relay is energized and hums when on 1,000 points, and off for 100 points. These Relays are
made to remain energized without doing any harm. With the playfield up, you should be able to
hear and see which relay is energized and making the buss. I think I have placed a small piece of paper
plate (the very cheap kind) between the plate and coil to reduce the buzzing..
What's the name of the game again, Top Machine?

#6 39 days ago
Quoted from Mopar:

Hey, good timing with the ears.
From your statement here, it sounds like the buzzing is coming from something like an alternative relay.
The Relay is energized and hums when on 1,000 points, and off for 100 points. These Relays are
made to remain energized without doing any harm. With the playfield up, you should be able to
hear and see which relay is energized and making the buss. I think I have placed a small piece of paper
plate (the very cheap kind) between the plate and coil to reduce the buzzing..
What's the name of the game again, Top Machine?

Chicago coin top ten

#7 39 days ago

I just checked your schematic link. From your description, I believe it's the "Change Relay"
that is doing the buzzing..

#8 39 days ago

It looks like it is Score Motor sw. C-1 that needs to be checked for the ball return problem.

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#9 39 days ago
Quoted from Mopar:

I just checked your schematic link. From your description, I believe it's the "Change Relay"
that is doing the buzzing..

Would you say this under the play field?

#10 39 days ago
Quoted from Gnrwarkfc:

Would you say this under the play field?

It could be on the bottom board, but I'd say most likely on the underside
of the playfield..

#11 39 days ago
Quoted from Mopar:

It could be on the bottom board, but I'd say most likely on the underside
of the playfield..

Ok found the change relay . It doesn’t sound like that’s we’re the the sounds coming from. It actually sounds like it’s coming from the first player drum unit (score reel) in the back box. Certainly sound like that’s we’re the soundbis the most intense.

However with that said what does the schematic say what the switches should be doing? Closed or open on the change relay?

Thanks so much everyone!!

#12 39 days ago

Also I’d more than happy to take a video so you can hear that sound and where I think it’s coming from.

#13 39 days ago

Furthermore it really seems like the buzzing is coming from the relay coil on the 1000 point reel in the machine. I pulled out the reel and the bracket holding on the relay was super hot. Way more than the other brackets over the other relays on the score reels.

Thoughts?

#14 39 days ago
Quoted from Gnrwarkfc:

I pulled out the reel and the bracket holding on the relay was super hot.

Yea, you don't want that coil staying energized for long.
Seems the 1,000 point relay is staying energized which is also
in the head. Hard to believe it hadn't burnt out after playing
a full game. I'd find the 1,000 point relay, then next time you hear
buzzing, check if that relay is remaining energized, but I wouldn't
leave it energized for long..

#15 39 days ago
Quoted from Mopar:

Yea, you don't want that coil staying energized for long.
Seems the 1,000 point relay is staying energized which is also
in the head. Hard to believe it hadn't burnt out after playing
a full game. I'd find the 1,000 point relay, then next time you hear
buzzing, check if that relay is remaining energized, but I wouldn't
leave it energized for long..

Can you tell from the schematic if the 1000 point relay switches are supposed to be opened or closed?

#16 39 days ago

Also what’s strange is the score reel cycles through and gets to zero and then the buzzing starts.

#17 39 days ago
Quoted from Gnrwarkfc:

Also what’s strange is the score reel cycles through and gets to zero and then the buzzing starts.

You mean at start up?
Yea, my guess would be there's a stuck (closed) switch on the playfield that scores 1,000 points.
I'd check all the switches that score 1,000 points. There's also a spinner right? I wouldn't think
that it's not it, but might as well check and make sure the spinner switch is normally open..

#18 39 days ago
Quoted from Mopar:

You mean at start up?
Yea, my guess would be there's a stuck (closed) switch on the playfield that scores 1,000 points.
I'd check all the switches that score 1,000 points. There's also a spinner right? I wouldn't think
that it's not it, but might as well check and make sure the spinner switch is normally open..

It fixed the buzz!! I did have a blade out of whack on the outline!! Thanks so much

#19 39 days ago
Quoted from currieddog:

It looks like it is Score Motor sw. C-1 that needs to be checked for the ball return problem.[quoted image]

Any advice on checking c1 on the score motor? What’s the switch supposed to be doing?

#20 38 days ago
Quoted from Gnrwarkfc:

Any advice on checking c1 on the score motor? What’s the switch supposed to be doing?

It looks like a NO (Normally Open) so check for proper gap and cleanliness.

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#21 38 days ago
Quoted from currieddog:

It looks like a NO (Normally Open) so check for proper gap and cleanliness.[quoted image]

Thanks so much. I hope I can type this next question clearly in a way that makes sense. How do I look at the score motor on my machine. Do I face it at the top of the machine by the flippers. I'm having a hard time knowing which direction I'm supposed to be facing to make it match the chart.

#22 38 days ago
Quoted from Gnrwarkfc:

How do I look at the score motor on my machine.

At rest, the "A" stack actuator is in the notch in the cam. Or count the switches. Or post a picture here.

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#23 38 days ago

So when I'm looking at the game from the front of the game (at where the flippers are) right in front of me should be stack A?

#24 38 days ago

No

#25 38 days ago
Quoted from Gnrwarkfc:

So when I'm looking at the game from the front of the game (at where the flippers are) right in front of me should be stack A?

Re-read post 22. They also may be labeled.

#26 38 days ago

Ok I found it. It was already open so I took a file and started cleaning the switch. However it’s still not fixing the problem. Actually now when the game starts the ball doesn’t kick out at all. It used to kick out on the first ball and none on the other balls. Any other thoughts? Is It possible I don’t have it clean enough? Or is it possible there’s something wrong with the coil?

#27 38 days ago

Jumper it so it stays closed and see what happens. Likewise, you can put a piece of paper in so it stays open and see what happens.

#28 38 days ago
Quoted from edednedy:

Jumper it so it stays closed and see what happens. Likewise, you can put a piece of paper in so it stays open and see what happens.

What does jumper it mean? Still in the process of learning all the lingo.

#30 38 days ago

Just hook one end to one solder tab and one to the other solder tab of the switch that you want to force closed.

#31 38 days ago
Quoted from Gnrwarkfc:

It used to kick out on the first ball and none on the other balls.

When you start a game, the ball doesn't kick out, but does the score motor run and keep running?

#32 38 days ago
Quoted from Mopar:

When you start a game, the ball doesn't kick out, but does the score motor run and keep running?

The score reel cycles through like normal and stops with no ball kicking out.

#33 38 days ago
Quoted from Gnrwarkfc:

The score reel cycles through like normal and stops with no ball kicking out.

It sounds like the Coin Relay is energizing the Score Motor, but the Outhole Relay isn't energizing at all.
You'll want to make sure the Bonus Unit is resetting all the way home and it's wiper has good contact
on its wiper board, and also the Outhole switches are making good contact when the ball is in its kick out
position and also a Make/Break switch is clean and adjusted properly on A2 Score Motor. A Make/Break
switch are three switches in the set where the center switch is either touching one of the outside switches or
the other. The Score Motor label may still be attached on the inside of the cabinet near the Score Motor stating
where the set of switches on the Score Motor cams are, and what the do.
Note: It's always a good idea to make sure the screws for the stacks of switches are tightened before
checking and adjusting..

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