Best source of info to learn EM repair

GoldenAge

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Hi, I have 2 EM pinballs that I recently bought. I'm intrigued by the EMs, the banks of switches are impressive, seeing them clacking and sparking away is incredibly cool. The fact that since these games contain no electronics, all the events are handled by on/off decisions, it all makes sense to me. PCBs either work or they don't, if it doesn't, I can't even begin to think about repairing one, but these machines are physical in their nature, moving parts throwing voltage to this destination or that one, making this happen or that, depending on this variable or that, it is a technology I can get my head around.

In theory anyway...

Both games have one or two little items that don't work, so I'm gearing up for tracking down the faulty switches or whatever it is that's ailing them.

But I'm a bit intimidated by the idea of poking around with these things powered up.

Is there a good book or other resource that gives someone a good overview of how to approach such a task?

Thanks very much,
Ryan
 
I fixed/restored one 70's single player Gottlieb. All I can say is get the schematic. Order one from Pinball Resource if you need to. That's all you need, and as little as I knew about them, and as frustrating as it was, I was able to follow the schematic and get the kinks worked out of it. Good luck.
 
+1000 on the schematics, makes things so much easier.

The pinrepair.com website (now offline) had the best info in a single place. Some folks are sharing copies of the content via torrent - do a google search if you are interested in that.

But if you are down to the point of troubleshooting specific functions, patience and the schematics are your best bet.
 
Fixing up my first EM, too. It's too bad Clay's PinRepair guides aren't around for you anymore. They contained a pretty good source of info. I printed them out as soon as he took them down via internet cache so I was able to get the 2009 version.

There's also the wiki that was started up after Clay yanked his site.

http://www.pinwiki.com

Anyone know if Pinthetic from RGP got his repair site going?
 
Thanks for the responses. Yeah, I have the schematics on both my games, and the games both work like 95% as far as the electricals go, it's just one or two little functions/events that aren't triggering.

Is it doable to work on these with the power on? If I know, for example, that this particular relay is the one that I suspect, can I manually try to trigger it with the game turned on to see what happens? The blue sparks shooting all over the place tell me I'm taking my life into my hands if I do that...

Or is it just a matter of not using a metal tool to "poke" with?

The idea of powering down, cleaning a contact, powering up, tripping the events from the playfield each time to test that specific event, well it seems tedious. But if that's the way it's done, then so be it.

I'll defintely check out that Wiki, thanks for the link, and will see if I can get a copy of the defunct site mentioned. I've seen numerous references to that site during searches on this one, now I understand why I wasn't able to get to it...
 
I engage the plastic actuator plates on the relays by hand all of the time when the machine is powered on. (just make sure you don't knock a leaf switch out of it's slot if you do this). If you are still a little freaked out about doing so, use a small wooden dowel rod or a ruler as your tool to push the plate.

Seems as if you've got a pretty good level of common sense already. Rubber sole shoes, don't stand in a puddle, and don't jam a screwdriver down there while it's powered up.

Realistically though - for cleaning and adjusting switches - you really need to power it down or you'll likely end up getting bit by your switch adjustment tool or whatever you are squeezing the leafs together with when you clean them. But if you just want to engage a relay when it's powered on, then no problem.
 
If you've got the schematics, that's key. Beyond that, try and learn about the various modules that make up an EM, and how they do what they do.

You'll have a main motor driven cam, which in turn activates various other modules - typically, one for the number of players, one for advancing between players, one for tracking what ball you're on, a bonus unit for keeping track of any bonus points, and the various scoring reels.

Know that when the game resets, the scoring reels all have to tell the game that they've all reset to zero, the ball counter has to tell the game that it's reset to it's home position (ball 1), and the same is true for the bonus and player count units.

Since yours are mostly working, observe them as they do their thing. See how they advance, see how they reset to their home position, and what switches are engaged/disengaged at each step.

If your game is mostly working, use the schematics as a guide to see what relays are directly involved with the feature that's not working. Ten seconds of cleaning and adjusting likely will resolve your issues - it's figuring out *what* to clean/adjust, and avoiding messing up anything that's already working that's the trick.

Know that many of those relays have pretty tight tolerances, so be careful making adjustments on the multiswitch stacks to avoid introducing new issues.

I spent about 8 months on my first EM getting it up and running - it's a learning experience, and will take time - but if you can learn it, you'll find that it just "clicks" one day, and you'll get better at pinpointing the likely source of various issues - whether it's an EM pinball, or an EM gun game, driving game, etc.

Oh - and don't use any type of spray contact cleaner - they're often flammable, and BAD THINGS can happen.

As for working on them with the power on - be careful, use common sense, but I find it helpful in that you can often more quickly find the flaky relay/switch that's causing your issues.

Good luck!
 
There's a series of articles on EM troubleshooting by Russ Jensen (alas, no longer with us) available here, as well as a bunch of other stuff.
 
Buy the book by Henk De Jager about pinball repair - it's distributed in the usa by Steve Young.
It's the best book written about e-m games, describing the operation and repair on every assembly you encounter on them..
 
Buy the book by Henk De Jager about pinball repair - it's distributed in the usa by Steve Young.
It's the best book written about e-m games, describing the operation and repair on every assembly you encounter on them..

that is a good book to get. it helped me fix the match unit on my gottlieb domino
 
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