Start button. Your problem is likely this M/B sw.

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Make/break. Read this from Clay's superb guide, then scroll to the top and bookmark: http://www.pinrepair.com/em/index2.htm#clean

This game has a step unit called the Player Unit. There's a detailed picture in the manual on ipdb.org. The Player Unit should reset at the start of the game and whenever the Ball Count unit advances. It could be that yours isn't resetting. First check if it's mechanically binding. With the power off you should be able to manually push in either solenoid plunger and let it go and have the Player Unit either step forward or reset with no hesitation. If that's not reliable it probably needs a good cleaning.

/Mark

@MarkG: If I'm not mistaken, it's the Coin Unit on this machine that controls the # of players.

@fotoboy: First locate the Reset relay, and the make/break will be easy to find because there are 3 blades. If there is more than one, look for the one with O-BLU (Orange-Blue) wire.
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Does it try to kick out the ball after 300 points? If not it may be that the Eject coil isn't getting a reliable pulse. Check the switch in the red box:
Cabaret Eject Coil (resized).jpg

Agreed. The Coin Unit certainly controls the 1-4 Can Play lights (among other things) and may not be resetting. Maybe the OP can elaborate on what the problem looks like. Which player(s) can score points? Does the Ball Count work, etc.

Then the Player Unit is probably stepping and resetting correctly.

Are you sure? That would make the Score Motor run constantly. Here's what drives it:
Cabaret Coin relay (resized).jpg
If it pulses off briefly the Score Motor switch is good and you'd just need to investigate the four normally open switches.

Do the score reels reset?

Here from the manual, which is available on IPDB:

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Note that it can also energize the Reset relay

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So, if you look at the snip in post 13, you see that the Reset relay, which you said is not energizing during start up, is powered by 'sw. C on the Coin relay when the Game Over relay is in the tripped position,' so check those that sw. for cleanliness and solid contact (snip of Coin relay in post 14).

and the Coin relay, which you said is sticking on, is powered by sw. B on the Replay relay.
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There are three switches on one of the power rails between the black wire (not labeled) on the left and the red wire on the right:
Cabaret power switches (resized).jpg
The red wire on the right side runs to most of the scoring devices so if any one of those switches is open or not making a good connection most of the scoring devices won't have power. This would normally be the case during game over or tilt for example. Much of the game still gets power even during game over or tilt so it can do things like reset or kick the ball out of the eject hole even if the game is tilted.