"Gottlieb AS Stepper" is a trigger word for me that my therapist says I should avoid at all cost. Nevertheless, I'll be monitoring this thread closely. Thanks for breaking it down OP.

Not exactly true. Many games use the Match unit to develop the "alternator" function for playfield features. Therefore, they do have an "every other step" cam and usually a normally open switch. It is this leaf switch that often causes additional friction on the system and prevents it from advancing.

Thanks for the nice picture-by-picture guide so those out there won't "fear" working on Gottliebs like some do.

Thanks for the photo illustrations. I've had lots of experience with these, and they still can be frustrating.
I usually do one side at a time. The nylon ratchet gear has a worn look even when new. The type without extra cams and switches (usually an alternating switch, or a zero position) are easier to get working properly because they don't have as much drag on them. Conversely, the ones that have two additional cams and switch stacks are the hardest to get working correctly. You can spend hours on those dang things! There are many subtle adjustments, including the little spring steel piece that is used as an anti-reverse and the armature stop plate that needs to be adjusted so that it allows only one increment of travel by the contact points. These can be a real bear to get working right, but practice and patience will make you an ace with these. Getting everything cleaned, aligned and running with as little drag as possible is key.

Ah, additional photos since I posted. New parts are of course very helpful! I've had to replace the wafer boards themselves due to burned off sections, but I usually scrounge parts from junk I have around. Thanks again for posting this.

It's assembled, but is it adjusted? There are many subtle adjustments to these critters. They can act balky if not properly adjusted. The armature stop must not allow too much travel, or the unit can increment two or more steps. The anti-reverse spring must be adjusted (it is slotted), so that when the ratchet gear is stopped against it, the slots in the ends of the gear shaft are aligned so that the contact points are centered on the copper traces on the wafer board. The boards also have oversized holes so that you can align them. Again, make sure that the contact points stop on the center of each contact land as you manually increment the unit. Adjust the board position as necessary to accomplish this, then gently snug the screws. The bearing arms need to be exactly parallel to minimize the drag on the nylon shaft. Coordinating all these adjustments is the hardest part to making these units work properly. Find a junker one and play around with it until you feel comfortable. Practice makes perfect. Now go and have that beer!

Yeah, those are nothing to rebuild without the switches....

I find it much easier to take the relay coil off (set it aside somewhere) and then soak the entire "AS" unit in Mean Green and scrub with a toothbrush. Then rinse off with hot water. Gets the whole unit clean without having to take it apart. Naturally, if there are worn parts then you'd need to disassemble it.

I clean all the gunk off the circuit boards with lighter fluid on a cotton swab or on a paper towel. Then I use 150 grit sandpaper on the copper foil then finish that with a quick swabbing of the fiberglass eraser pen.

I smear a thin coat of the Radio Shack clear lube gel on the copper foil.

That's cheating! Real techs disassemble!

I had one once on a "Sheriff" that was totally not working. It was the one that controls the horseshoe lamps. IIRC, it had two cams with two switch stacks. One was to increment the bonus level up when the unit completed a cycle, and the other was a home position runout that returned the horseshoe lamp to the first position at the start of each new ball. That one was a bee-eye-itch to get working right!

I know this is an old thread, but I wanted to say thank you! I took my FS Relay (00-90 unit) apart today, cleaned it, and put it back together. It wasn't working before but now works well!

Thanks for this!

Dude, that carpet...

I'm having trouble with this exact function on my Flip a Card.

2 issues. The extra friction you talk of really is there and it seems to hang things up.

But I believe the center bumper should alternate on and off with one pt scores.

It only lights on 9.

I'm guessing something is amiss on this simple relay.

But tHe match function works fine.

Nice job Chris. I've done this a few times, but it's always nice to have your instruction to follow.

Make sure the armature return spring isn't too tight. I had this happen with a Top Card. Someone had shortened the spring and it was too strong. The plate wouldn't pull in enough to move the gears close the n/o switch and make the alternating relay do its thing. I put a proper spring on there, case closed.

Great tip EMsInKC. I had exactly the same thing occur on an Abra Ca Dabra AX relay. It took a while to diagnose but now an early point of call!

Dude, that towel...

I've had issues with this match stepper on three several games lately, Fast Draw, Royal Flush and Target Alpha. I wasn't even thinking this was the issue, but it also is used to trigger the alternating relay. Had to take it apart and clean each one like you show.

This stepper on my El Dorado often lights two match numbers at the end of a game. If I actuate it by hand, I can never recreate this, as it always steps through properly and lights one number at a time, but it must be slightly mis-aligned or half-stepping or something. Has anyone seen this before? Does anyone have any recommendations for what to look at?

I disassembled and cleaned this stepper last year.

Probably misaligned. The screws that hold the arms that puts pressure on the wipers can be loosened. The bakelite pieces, with the traces on them, can be rotated slightly. Make sure the wiper arm is centered on the trace before tightening the screws.

The metal wipers wear slots in the Nylon ratchet wheel. Then their is play and they align incorrectly, sometimes bridging two circuit traces, sometimes one. Check if the wipers can be moved without the Nylon ratchet wheel moving to see if yours are have excess movement. You can buy the new ratchet wheels from PBR, which cures the problem.

Thanks, folks!

. . . and as any HHGTTG fan knows: "You should always know where your towel is".

Thanks Chris for an excellent tutorial.

I just reviewed this ancient thread and it should be a sticky in the EM forum. Some good info.