(Topic ID: 302763)

Always has 3 players active

By Dodgers

2 years ago

Topic Heartbeat

Topic Stats

  • 12 posts
  • 6 Pinsiders participating
  • Latest reply 2 years ago by Dodgers
  • Topic is favorited by 2 Pinsiders


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#1 2 years ago

Greetings, I have recently purchased Williams Space Mission and have two issues that may be related.
First - when pressing the start button it always has 3 players active unless you press start again then it has 4 .would like to get it to 1 2 3 4 when selected.
Second - it is currently on free play , the credit counter does show credits being used . But I'm a weird one and want to get it back to coin operation . It's part of the nostalgia for me .
Any clues as to what to look for ?

#2 2 years ago

The first issue involves the coin unit not resetting completely. On the gear side of the unit, check the switch activating pin on the gear. It should be opening the switch from below. If the pin is above the switch, the reset stroke won’t allow the gear to reset properly.
The free play issue involves the credit unit switch that is adjusted to stay closed even at zero credits.

#3 2 years ago

First of all thank you for your reponce !
It currently has no coin unit , just cut wires . Two of which I assume were for the light .
I'll check the other latter today. Thanks again

#4 2 years ago

Pinballdave was referring to the Coin Unit which is a stepper located on the bottom component board inside the cabinet.

#5 2 years ago

Welcome! Before we can help you, you really need to start getting familiar with the machine and it’s parts. You will find the manual and schematics here.


#6 2 years ago

Page 18 in the manual

I suspect this unit is not resetting. Here are the switches you should check.

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#7 2 years ago

Also verify the coin stepper moves freely when manually stepping it up and down. It could be gummed up and needs taken apart and cleaned.

Edit: Here is an excellent guide on EM pinball repair to help you out.

#8 2 years ago

As ArgosySK and kguenther6 wrote about, it is most likely that your coin unit stepper is not resetting properly and the spider on the back side is not rotating back to the 1-player position at machine bootup.

Below are rough pics of a typical coin unit from a Williams 4 player machine of your vintage. The first 2 photos depict the spider side of the coin unit in the 1-player and the 4-player positions, respectively. Note than in the 1-player position, the longer arm of the spider is oriented pretty much straight up at 12 o'clock, while in the 4-player position, the same arm of the spider has rotated counter clockwise by 4 steps on the copper trace. The 3rd and 4th photos depict the gear orientation at the 1-player and 4-player positions, respectively.

The peg and switch referenced by Pinballdaveh are seen in the lower left quadrant in the 3rd and 4th photos. That switch, when opened by the peg from underneath, effectively disables the credit button from wasting credits if someone mistakenly tries to add any more players when the stepper is already at the 4-player position.

The coin unit stepper gets reset by a clockspring around the gear shaft that gets wound up when multiple players get added. When the machine is booted up (first for one player), the reset solenoid plunger pulls in and pulls the stop away from the ratchet such that the clockspring can rotate the spider/gear back to reset position, but sometimes, the stepper mechanism and gear shaft get gummed up and the clockspring does not have enough force to rotate the stepper back all the way to reset. This failure can also occur if the peg mentioned in post 2 gets on the topside of the switch on the gear side.

As kguenther6 was suggesting, you can check for free movement by operating the coin unit stepper with the game off by manually depressing the plungers on the advance solenoid and the reset solenoid to determine of the unit is advancing thru players 2, 3, and 4, and then resetting back again. If not, you likely have one or more of the following:

1) gear shaft is gummed up and sticky.
2) spider arms on backside press down on the traces with too much tension (increased friction) and could use to be adjusted.
3) copper traces need cleaning and a very light film of teflon lube to reduce frictional forces.
4) Someone perhaps unwound the clockspring by 1 or 2 turns, such that it does not have enough tension to fully reset the unit.


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#9 2 years ago

Once again thank you !!
The stepper switch had to issues , primary being the second relay doesn't fire . I didn't have my meter to see if it gets power or not but now I know it's either the coil is bad or the switch that energizes it has an issue.
Secondly , the tension on the spring was not enought to spin the wheel back ( that part is fixed ) at least I have one player back for now.
The free play was very apparent once I new what to look at , as you can see it the picture , somehow I don't think the wire nuts are factory..lol All I should need now is how they should be wired .
Can't thank you enought for the help !!!

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#10 2 years ago

Hmmmm wish I had read all the additional post before working on it . You were all spot on in your suggestions.

#11 2 years ago

The 3 switches on the credit unit have been removed and the wires wire nutted together. New switches need to be added to return to original coin operation.

#12 2 years ago

Guess I will live with no coin op for now.

On another note , I found why the solenoid was not firing. Somewhere alone the line this happen . Put the leaf switch back on the correct side of the post and ( poof ) player selection is back to 100% .
Again thanks to all helping thru the learning curve !!

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