I use alcohol, a dremel with a 443 tip, and then clean with alcohol again. You can use your favorite cleaner in the middle step although a flexstone would be much better than a fingernail file.

Sanding a dirty or fouled contact won't clean it

Whenever I can fit it in I use a 443 dremel brush, and then check the contacts to make sure they make good contact after

A wooden fingernail file is WAY too wide, thick, and rigid, you likely knocked some switches out of adjustment. This is why pros generally don't reccommend that newbies "shotgun" a game and "clean and adjust" every switch in the game, you are more likely to cause problems than fix them.

You need the proper tools, rather than whatever you found in the bathroom sink drawer: simple and cheap - soft "flexstone file," hard metal file, and a switch adjuster. Call PBR at 845-473-7114 today and get them.

This is pretty much the bible for EM pinball repair and maintenance. Learn it. Live it. Love it.

http://www.pinrepair.com/em/

Completely agree with the alcohol and dremel where you can. If I cant fit the dremel a flexstone is the tool. It does sound like you probably got one or two out of adjustment. You will find it. Just go through them one by one

$1 flexstone files have done a fine job for me for 20 years, a power tool seems kind of like overkill to me.

I use some sandpaper...usually 400.

What's the flexstone issue? Have they stopped making them or something? I thought I saw something aboot it

I used to use fine sandpaper until I found one of these files in a pinball I bought.

I usually use isopropyl alcohol and a q-tip to remove what I suppose is the silver oxide on the contacts. Sometimes the file or flexstone is employed, especially if the contacts are pitted or otherwise not mating well.

And always operate the switch stack to ensure proper opening/closing. The switches should not just touch, but bend a bit when they are closed. Sometimes the amount of travel in the relay or mechanism is small and it is a finicky job to get them properly adjusted.

The joy of an EM is that a single wonky contact can make things not work!

Also, don't forget to tighten the switch stack if possible before cleaning/adjusting. The bakelite shrinks over the years and these stacks get loose.

Everyone always says this, I've never found it to be the case. Maybe just lucky.

I often get like 4 or 5 turns on the screwdriver!!!

Not every game is like this but it's very common in my experience.

I think you've had a lot more games pass through your hands than me! I'll consider myself lucky and check on my next EM project.

Oh tighten for sure; hit or miss

Yep, this takes care of a lot of problems right up front. I actually do this before turn the game on for the first time.

I’ve had some that turn just a little and others were so loose I could tighten with my finger. I think GTB had it the worst.

Agreed that a flexstone and swtich-gap tool are requirements! But if you don't have them handy:

I use business cards (not modern smooth and glossy ones, but the kind that have a fibery texture) to wipe contacts. On especially dirty switches I dab a little alcohol on the card strip BUT that makes them disintegrate quickly. On especially grungy games I prefer disposable business cards as opposed to messing up my flexstone, etc. And you can bend and fold them to work with all kinds of mechs and gaps.

I also laminated some 800grit sandpaper to a flipper gap tool and that has worked VERY well: just a tad more flexible and finer than a flexstone for certain areas, or the occasional gold-plated contact that really shouldn't be filed but is for some reason too @&*@ stubborn - out of desperation (because you don't always have a spare new one handy).

As for tightening the screws: it almost never hurts to do so, and might solve (or prevent!) an issue. Don't go crazy, just cinch 'em up.

And while you're doing that, eyeball the switch stack spacers and the little white nylon parts, and see that the make/break action appears to makes sense. You will have to analyze what's happening at first, but once you get the "eye" for it, you can quickly tell if things look proper not. Turn the game off and gently press a relay or stack to observe. If the contacts stay closed or open even when the blades are moved by the mechanism, that's normally a hint to investigate further.

I'll have to look, but last time I checked, PBR didn't have any flexstone files.

Flexstone no longer available, but he has Plastone. Not sure if that's what we've been using all these years, but it seems to be a suitable substitute.

I have learned not to trust my eyes when it comes to knowing if a contact is touching or not. I use a multimeter and check the resistance, then there are no questions anymore.

Alberto

If you had a working game, and it’s now not working, it’s because you have a switch out of adjustment. Not because you have a dirty switch. Don’t waste your time going back through and cleaning them again.

Recommend posting a new thread telling us where in the startup sequence it stops. From there you can get help to readjust that switch and you’ll be back in business.

It’s usually something simple.

Also, cleaning switches with a dremel wayyyy over the top! A swipe or two with a flexible file is all that’s necessary most of the time. (And most of the time, it’s not even a dirty contact that’s causing the issue.)
The point is to remove any contamination, not switch contact material.

Nothing personal, but based on your posts you should try to find an EM tech. My guy charged me about $120 but I learned a TON watching him and letting him talk.

Shotgunning a mostly-working EM is a bad idea, IMHO (I’m speaking from experience). Get a schematic, find the most likely relay or switch stack for your problem and put those under a microscope.

If you post the specific problem, you’ll get lots of support in this subforum.

All of this is spot on.

Dude goes back in there with a friggin power tool he’s gonna make this worse. Much worse.

OP needs to figure out what he messed up the first time around, not go back in and “clean” everything all over again.

OP - put the power tools away, take a break, and wait for your PROPER em tools to arrive, especially the switch adjuster.

Sorry but that was a mistake. This forum is full of posts from people who tried shotgun cleaning & adjustments, and caused more problems than they were originally trying to solve.
What to do instead: Slowly and carefully diagnose one problem at a time and then fix only that.
http://www.pinrepair.com/em/index2.htm#clean

If the Replay button doesn't activate the Replay relay, Inspect and diagnose this circuit with Alligator clip jumper wires

https://pinside.com/pinball/forum/topic/gottlieb-big-shot-repair#post-6305153
http://www.planetimming.com/Pinball/troubleshooting/EM%20Troubleshooting.pdf
http://www.pinrepair.com/em/index3.htm#features
Example of a pinsider actually doing this https://pinside.com/pinball/forum/topic/red-baron-tech-question#post-5858156

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I think David mentioned that the Plastone files tend to leave a dusty residue on the contacts after use but after a while, the coating on them which produces the dust wears off anyway and the file is still good for some time until its spent. I like to run a brass bristle miniature wire brush over the contacts anyway, just freshen them up so any residue is removed. And yes to tightening the stacks before working on them, they left the factory tight so keep them that way.

It depends on what you're doing. If you have the game apart and are cleaning up all the relays, meaning taking the relay apart, then using a brush on a Dremel is really fast and really cleans up the contacts. If you're just trying to clean up a random dirty switch in the game, then no. That's when you're likely going to mess it up trying to get the brush in there. But when a switch stack is free from the armature they work great.

You have never, ever, had a switch stack that has loose screws? That's really hard to believe. I rarely find them that aren't loose. If you do find that, someone has been in front of you working on it. If you get a game that has been sitting for a long time, they will all be loose. It's almost a guarantee.

I would agree that you probably shouldn't try and clean up all the switches if you're new to working on them, AND the game is mostly working. But when you have a non working game, really grimed up, you're going to be ahead cleaning them because there's no way to just solve one issue. You're going to have to clean them, and you're going to have to clean up the steppers. It doesn't matter how much you clean switches. If steppers aren't working, the game isn't working. And score reels are steppers too and cause no end of misery in non working games.

I think the upshot is, I need to get off these DMD machines and work on more EMs! Well I am -- first pitch & bat so I'll pay particular attention to those switch stack screws.

I cut uncoated Food Lion paper plates in to strips. Then halve those.
Denatured alcohol 92% from Dollar General.
An ignition points file found in my first EM (Klondike).
The card stock of these plates match Business card stock.
The irregular ridges pressed in to each plate helps.
Very light strokes from the ignition file after cleaning, just the Crown of the point, clean again.

Of course after first tightening the switch screws.