Help with Space Mission

Sirius

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The problem started with it not scoring the special when hit. It was more of a hit and miss, sometimes it would register and sometimes not. Also when you reached the free play score, same thing, sometimes would give a game and sometimes not. Then one day I turned it on, hit the start button and the score reels reset but the machine wouldn't stop trying. I found that problem...a wire had detached from one of the score reels. I reattached and that and that problem was solved. But now when I try to add credits via the coin slot...nothing happens. I can reach in the machine and energize the 10 cent coil and it'll add credits. I'm not all that familiar with the EM's. I have checked all the fuses, switches and contacts and all seems good? Everything that's supposed to be closed are, and everything that's supposed to be open is. I have the schematics, but they are difficult to read and the wires in the game have all faded and yellowed and are hard to distinguish apart. Any help as to where to check would be great.

I closed the switch on the credit reel to give free play and the game starts and plays fine with the exception of the problems listed above. I know this isn't a big deal and the game plays fine the way it is...but is it just me or does anyone else love the the sound of the knocker when you score a special or free play? I do, and I want it BACK!

Thanks...
 
I'm just guessing, because I don't have the schematics, but between the both of us, we should be able to narrow it down a bit.

Problem #1: Not scoring special.
This could actually be related to Problem #2. There should be a credit unit (with the reel showing how many credits you have left). It's possible you are at the maximum, or there is a set of switches on the unit itself that tells the unit that it's "ok" to add a game. If this switch is out of adjustment, you'll never win a replay. This is close to your "free play" switch. Probably in the same stack.

Problem #2: Score thresholds not scoring.
This could be the credit unit also, however there are bakelite discs that are on some of the score reels. I would take the score reels apart, clean these discs, make sure all the switches are setup correctly, then put it back together. It's possible that when the score reel is at the threshold, it's just not making continuity.

To fix both of these, I would honestly take apart every score reel in Player 1, and rebuild / clean them. Also, make sure the credit unit is stepping up manually, nice and clean. If it's not, then take that apart too and clean / adjust it and put it back together.

Since it's a williams game, you have access to the parts catalogs online (www.pinball.com). They show views of the units you're going to be fooling with. I don't see an exploded view, but it's pretty easy to take apart and clean. Take plenty of pictures.

When all is said and done, the nice thing about EMs is that they will pretty much work for a very long time, after you have systematically cleaned and adjusted the units. When the game is operating, it actually "cleans" itself, and you'll be surprised about things that all of a sudden start working, because it was sitting so long, and switches needed to be cleaned.

Hope this helps, I'll check back now and again to see your progress.

-Pat
 
Thanks Pat, I've been doing some checking on your suggestions. As for problem #1, the switches are all in adjustment. As for the "free play switch", there isn't one on the Space Mission. It's a matter of closing the switch or jumpering it. One thing I have noticed is the match unit has quite a bit of wear on the disc (see pic) from the contacts turning on it. This causes some of the match #'s to not light, flicker and dim at times, because of the poor connection. I know this is not the cause, but if these are worn, I wonder about wear on the score reels? Is there a method to repair the wear on the traces? Another thing I noticed is that it if it decides to score a special...it will score the threshold or vice verse, but will still not add any credits via the coin slot. Also if it doesn't matter what player its on. I checked the voltage at the coin switches and I have 13v AC. Seems that the more you play, the more likely it works, but will never add credits via the coin mech no matter what the position of the credit reel.

Thanks...
 

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If the special works sometimes, then it's probably a switch that needs cleaning or out of adjustment.

Check the "special relay" and verify all of those switches are clean and adjusted properly.

I'm not that familiar with Williams off the top of my head, however when I apply the typical em logic, there should be a wire that runs from the coin switch to that actual relay. Check in your schematic for the relay name (is it the 10 cent relay?) and then look back for the coin switch. Every point in between those 2 items needs to be closed (I would imagine) or activated so that it's closed with the coin switch, or it won't pull in the relay.

Unfortunately, there really isn't a way to repair the "cut through" traces on those bakelight discs. The fingers need to slide around easily, and if you have a blob of solder in between, it makes it difficult. I've heard of some people attempting a repair, but I've never heard of how successful they were. You may need to find a parts unit, and take the disc out of it.

The more you play the game, the more that things will start working, because the switches are cleaning themselves by being activated. This is why they become so reliable the longer you play them.

-Pat
 
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