On my Lucky Hand KS relay mini stepper I just used 91% alcohol to clean and it was really gunked up and sluggish. It cleaned up nicely but it turned out that I had to get those switches adjusted just right to keep them making without putting too much pressure downward on the rotating gear.

I’ve seen people say that a light coating of Super Lube on the wipers helps but I’ve never had to.

tighten screws
Lighter fluid to clean gunk off
Sandpaper all the traces & wiper to get them nice and clean
More lighter fluid to get any remaining crap off
Thin layer of super lube to get everything moving nice
Maybe clip that spring a bit to shorten it & get it nice & tight...if needed.

MarkG turned me on to mineral spirits as a cleaning fluid. Does a great job washing off "gunk".

In my experience alcohol is good for removing soot, grit, dirt, light oils, etc., hence its popularity. But when it comes to removing anything grease related I prefer mineral spirits. It cuts through grease better, probably because it's petroleum based like grease, and it has a longer working time because it's less volatile than alcohol.

I’ve rebuilt quite a few of these little annoying assholes.

Some takeaways that make it less maddening (for me):

—for the printed circuit boards, I clean with brasso or equivalent. I really *really* don’t like sandpaper in any application like this. Polish that sucker up to a bright shine. I do this without removing the wipers. I just work the relay around to get all the areas.

—I clean the plastic gear inside with a q-tip and some naphtha.

—AS relays with a larger switch stack inside are way harder to adjust to click freely without sticking. In these applications, sometimes it helps to do little micro adjustments to the switch(s) to reduce tension, but still allow contact.

—I always finish the circuit board up with a very thin film of Teflon lube or PBR grease.

—Clicking the relay by hand out of the game doesn’t always predict how it’ll work in-game. So if you are having trouble getting it to advance properly with your hand, but you’ve tried everything, more often than not, the super quick pulse by the game will give it the rebound it needs to actually work in-game. You can kinda emulate it out of the game by “flicking” the actuator plate with your thumb or finger. If it advances under those conditions, you’re good to go.

Less is more with these things, so don’t overdo it if you can help it. They’re honestly not as bad as a lot of people say they are. They just take time getting a “feel” for them.

These links can be helpful
https://pinside.com/pinball/forum/topic/gtb-as-match-stepper-rebuild-step-by-step
http://www.pinballrebel.com/pinball/cards/cards/Used_cards/Gottlieb_AS-relay_Adjustment_B-11492.jpg
Parts: http://www.pbresource.com/relay-GTB.html#gtb-as

<<You can kinda emulate it out of the game by “flicking” the actuator plate with your thumb or finger. If it advances under those conditions, you’re good to go.>>

I pull it down with my fingernail, then let it flick off to get a full stroke.

Make sure that the little white nylon anvil shaped part that engages to the cog on its shaft can also slide. If you look at it carefully, you'll see a little spring in its base to allow it to slide in its housing as it engages.( no.3 and 5 on the picture.) And I like to lightly use a contact file across the tip of coil to allow maximum current to pull the armature down.

I’ve used a toothbrush and 91% alcohol to clean off the ratchet cog without disassembling the relay. I also applied Super Lube to the switch cam on the AS relay that controls the bonus on my Royal Flush when it was malfunctioning. Now it consistently works properly.

I agree with the suggestions already mentioned. I’ll add a couple of other fine points.
Super lube works great on the circuit boards. You can find it at a decent hardware store.
Make sure the plastic axle is nicely centered in the little arms that they ride in (and hold the wipers) when you tighten the screws down.

I use mother’s mag and aluminum polish on the circuit boards to get the copper looking new. The brasso probably does just as well. I’m also not a fan of abrasives on these boards.

As you saw, previous hacks of just adding lubricant is usually the thing you’re fighting. Make sure the little wipers are clean and have a little tension on them that they make contact with the trace.

It took me a few times with these things, but now they are no big deal, especially when you can unplug them and do them at a bench. The links shared previously were a huge help.

Good luck,
Dave

Is there any wear on the back of the armature where it hits the top of the coil? Sometimes the coil digs a divot into the armature such that the two mechanically (not magnetically) bind together. Deforming the divot with a flap wheel or something similar can prevent the mechanical binding.

/Mark

Or replacement if one has spares. I often change them on the 10s/100s/1000s relays of Gottlieb games since they are in constant use. The pivot points also get worn and sloppy.

The switches on these old EM's can arc. We've all seen the sparks.

Isopropyl alcohol is flammable. So is lighter fluid.

Use extreme caution if using these as cleaners. Better be very sure there are no vapors or residue.

I wojldbt worry too much aboot it; we use a ton of lighter fluid and nothing has flamed on yet

Put them in the freezer for a couple of days, and the residual magnetism will be eliminated.

Thats a first! Following to see if anyone can confirm.....?

Coyote, the PBR EM lube is awesome stuff, its all I use and that little tub of it should last forever.

Google search is showing the use of magnets, striking with a hammer or heat.

Yes. It's safer than heat or striking with a hammer. It works.