(Topic ID: 225941)

Advice needed for Williams Skylab machine

By valveamp

4 years ago

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  • 16 posts
  • 2 Pinsiders participating
  • Latest reply 4 years ago by valveamp
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#1 4 years ago

Hi. I'm hoping someone here can point me in the right direction on a Skylab machine. There are 2 problems, but they may be related. These just showed up recently. Before that, the machine was playing well. The first problem is at game startup. Instead of giving the normal 5 balls, the ball count will go all the way to 10. After that, the machine plays normally. This problem occurs somewhat randomly, not all the time. The second problem is related to the SPACELAB bonus. A little background, there are 6 lights around the field that spell SKYLAB. When the correct target is hit, one of the lights goes out. When all of the lights are out, the SPACELAB bonus lights 2 lights. There the are other targets that will light one light on the SPACELAB bonus. The more lights in SPACELAB, the larger the bonus when a ball is drained. When the SKYLAB lights make the 2 SPACELAB bonus lights light, all of the SKYLAB letters are lit again and you can start over. Sometimes, the SPACELAB bonus will go beyond 2 lights and just keep going until they are all lit and it will still try to keep lighting them. In other words, the score motor is still on and relays are firing. Hitting the game start button will cause the machine to go into a reset where the SPACELAB lights are sequentially turned off. I'm wondering if this is really 2 separate problems, or is something keeping the score motor running and it's impacting both the ball count and the bonus count. I've looked at and done some adjusting to the switches on the score motor unit, but this hasn't helped. Any help would be appreciated. Thanks much.

#2 4 years ago
Quoted from valveamp:

at game startup. Instead of giving the normal 5 balls, the ball count will go all the way to 10

If the game works correctly when set for 3 ball play, this motor switch is probably gapped too close.

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#3 4 years ago

So, your advise would be to set the machine to 3 ball play and see what happens? It is currently set for 5 ball play.

#4 4 years ago


#5 4 years ago

Ok, mostly bad news, but just a little bit of good news. The bad news is that, occasionally, with the ball count set to 3, the machine will initialize to 8 balls, then play normally. So, I have to say that moving it to the 3 ball mode didn't change anything. The small amount of good news is that then I first moved the selector from 5 balls to 3 balls, it didn't display any balls. After several new game attempts, it would show 1 ball. This turned out to be the score motor switch 3D, for 3 balls, was misadjusted. I adjusted it and immediately got the expected 3 balls per game. So, in a small way, I made the machine a little better (good news). For some reason, it didn't go to 10 balls as it had previously when set for 5 ball play. Not sure why. Let me know if I'm wrong, but this check (fix?) has nothing to do with my problem associated with the SPACELAB bonus turning on too many lights. I think it's just looking at the problem of initializing to more than the selected number of balls. I did not check the score motor 5D (5 balls) switch as the problem seems to be independent of the ball count selector. Any other thoughts?


#6 4 years ago

just and update.......The machine will go up to 10 balls in both 3 ball and 4 ball selector positions. It also keeps running for a while after it hits 10, then will, finally, stop. I also adjusted the advance unit, a little, hoping that would solve the bonus problem. The fingers on the wheel seemed to be slightly off. So far, I have not been able to recreate the bonus problem, but it's too soon to declare victory. I'll keep trying to make it come back. At a loss for what to do on the ball count at initialization problem.


#7 4 years ago

More updates........the advance unit adjustment did not work. Still getting multiple Bonus lights after SKYLAB is all lit.............

#8 4 years ago

Does the Coin relay hold on for the entire time the balls are counting up?

#9 4 years ago

Hi. I just lifted up the playfield and held it up with the lift bar on the side. I then took my phone camera, set on video, and pointed it at the coin relay, then pushed the "start game" button on the front panel. I couldn't really see the ball count, but I could hear the coils in the ball count stepper moving. When I put the playfield down, the ball count was on 10. From what I could see and looking at the video, the coin relay WAS held on for the entire time the balls count was going up. I'm trying to understand what creates the ball count on game start. Obviously, the ball count step up coils is being pulsed, but what stops it at either 3 or 5? The only difference the 3 or 5 ball adjustment, in the back box, makes is to use a different cam/switch on the score motor. What actually stops (supposed to stop) the ball count from going beyond 3 or 5?

#10 4 years ago

During game reset
The Ball Count step up coil is pulsed through the Coin relay.
The Coin relay is held on through the score motor switches in my earlier post
or through one of these circuits.

If that doesn't help you and you'd like to try a phone call, send me your phone # in a private message

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#11 4 years ago


Thanks for the information. I just have a a couple clarifying questions. If I can't get it after that, we can talk on the phone. Your statement "The Coin relay is held on through the score motor switches" implies, to me, that when one of these switches (3D or 5D) opens (switch in use selected by 3 ball or 5 ball selector) the coin relay will turn off (de-energize), thereby stopping the pulsing of the ball step up coil and, therefore, the ball count to stop incrementing. If these switches, 3D or 5D, are operating correctly, then what's keeping the Coin relay energized is something else and that something else is most likely highlighted in the red lines in the schematic you provide above. Do I have that correct so far? The other paths, that are supposed to be "open" circuit at restart are the 5 cent switch, 10 cent switch and, maybe, the 25 cent switch. All of these go through the 10 cent and 5 cent adjustments. I wonder if I can just open up the coin adjustment switches and eliminate that path as a source keeping the coin relay energized (??)

Somehow (may not matter to this problem) the difference between a 3 ball and a 5 ball is the amount of time the switch (3D or 5D) is actually closed.

I think I'll disconnect the coin adjustment switches and see what happens.

Thanks, again.

#12 4 years ago

Oh, forgot about the 5 cent relay switch. I'll check that also....................

#13 4 years ago

All that sounds right.

#14 4 years ago

I can't find the 5 cent relay. It's shown in the schematic, but not in the manual. Can you tell me where it's located? Guessing the marker label came off. Thanks.

#15 4 years ago

My copy of the manual doesn't show the 5, 10 and 25 cent relays. Yours might if you have a paper copy.
If you have a 5 cent relay it would be on the Mechanism Panel (bottom board with the motor)
Do you have the 5cent adjustment?

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#16 4 years ago

Hi. I wanted to give an update on my issues with the Skylab. To answer the question from HowardR, yes, I do have the 5 cent adjustment, but I have 2 coin mechanisms on the front panel. Both say "2 plays for 25 cents". I don't know if these mechanisms work for 5, 10, and 25 cent coins, or just 25 cents only. These mechs are all there, but are not working properly and I haven't spent much time on them. Back to the ball count (over count) problem, I looked at what actually stops the ball count step up. I cleaned 2 contacts on the coin relay. Right after that, the ball count started counting properly, but would occasionally over count. This was a reverse of what was happening previously. It would over count most of the time, but occasionally stop at 5. I did some adjusting and cleaning of switches on the coin relay and the game relay M/B switch. As of right now, it is working. Although, it did overcount once over the weekend. I suspect that, possibly, there is a tiny adjustment of a switch I need to make, but I'm happy that it's much better now. Regarding the problem with the bonus count (SPACELAB) lights, I made an adjustment of the advLance unit. The fiber board with the contacts was not aligned with the rotating switches. Loosened the board (2 bolts), rotated the board and retightened the bolts. So far, so good on that, no problems since. This machine has a history of working well, then coming up with some problem, get it fixed, plays well for a while, then another problem. If it keeps this up, I'll be a Skylab expert...... Anyway, I want to say thanks for the help, especially from HowardR. I'm keeping my fingers crossed that it's all good now.


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