I've never used grease on any of my steppers, although I've seen others swear by it, with the caveat that you use a very LIGHT coat. You may have too much grease on yours.

You need a dielectric non-wax based silicone grease.

PBR’s stuff is great. It’s the real deal they used back in the day. Perhaps you have too heavy a coating. It should be very thin.

Double check the alignment of the disc and wipers make sure it’s not gapping two together.

I'm curious. Which pads, and while the stepper is stepping up or resetting?

The red glow and smoke indicate heat, likely due to current flowing through a high resistance, probably a lot of current. I wonder if the stepper should be moving while the pads are live or if the the Bonus Unit should be idle while the pulse (maybe from the Score Motor) comes through.

There's a map of the Bonus Unit contact disc in the manual (https://www.ipdb.org/files/1298/Jive_Time_Manual.PDF) on page 15. Is it contact 1, 2 or 3 that are smoking? Those drive solenoids (higher current) while the other contacts drive lights (lower current).

/Mark

Depends on how old it is.
Old lithium/wax based greases will separate in the tube, where a semi-clear fluid will present itself upon being used after a long period. This fluid is usually mineral spirits based and while not flammable it is combustible under the right conditions.

Still, there should not be any smoke of quantity coming from this unit.

From experience with steppers (and score motors) being heavily used in establishments, light grease (Super Lube)
has been a huge plus, and never experienced it causing smoke. I've seen arcs on the backside of wiper boards (arcing
solder joints), but there's also times I had sworn the wiper board's front side was 100% clean, but yet have seen small
arcs between the wiper board's rivets (pads) which many times disrupted the machine's accurate performance..
I'm thinking that you probably noticed it in relatively the same area(s). What I did (and what it took) is run a razor blade
knife between the wiper board's rivets a few times and that removed the micro conductant substance (rivet filings (?)
that the naked eye wasn't able to picked up. I'd maybe recheck the Bonus Unit's wiper board once again..

Do you mean the spinning arrow in the backbox? The one driven by a motor and not by solenoids like a step unit? There's some discussion of that in the manual (on IPDB.org):
Jive Time Spin Unit (resized).jpg
As the arrow spins a wiper on the board selects one of six relays to determine what the award will be. I don't think those relays should fire while the arrow is spinning though because of the Delay relays. The Delay relays should only allow current to run through the wiper board once the motor has stopped.

If you're seeing smoke on the wiper board are you also seeing the six relays firing one after the other? I don't think that should happen.

Perhaps the grease may be participating in the smoking, but it's
the arc that's causing it..
Throughout the years I checked out quite a few, and I have to
agree with the majority. This Synthetic grease is the grease to
use. Doesn't gum up in time..

https://www.amazon.com/Super-Lube-21030-Synthetic-Grease/dp/B000XBH9HI/ref=asc_df_B000XBH9HI/

Where theres smoke, there’s fire! It’s not the grease.

Check to see what coil is being operated by the contact on the stepper disc that is “smoking and glowing red”. If this coil has shorted turns, it will cause a large voltage spike when the stepper finger leaves the contact. Sometimes you can tell if a coil has shorted turns by the way it looks, as it will have a crispy wrapper.

Here’s some more details of what could be going on from the Pinrepair guide:

So Why the Big Blue Spark?
The only reason a switch gives a big blue spark is if something is consuming masses of current. And the only way that happens is if there is a low ohm coil in the circuit. Low ohm coils are nearly a dead short (very low resistance), hence they consume lots of current.

The blue spark is caused by EMF - Electro Motive Force. As any energized coil collapses, it back-spikes *twice* the game's voltage back through the switches. That means if a coil is energized at 25 volts, it will back-spike 50 volts. The lower the coil's resistance, the more EMF and the larger the back spike. A big blue spark can also happen on stepper units. Remember a stepper unit is merely a big stack of switches. As the fingers move from stepper pad to stepper pad, a "switch" opens as the stepper fingers move off a copper pad. If a stepper unit's bakelite pad is burning, there is most likely a low-ohm coil in that circuit causing the big blue spark and burning the bakelite copper pad. This happens as the stepper's fingers move *off* the burnt pad (and a low-ohm coil collapses causing back flowing EMF to burn the pad and cause a big blue spark). Note Gottlieb sometimes used a 8200 ohm resistor (or other value) on stepper units or coils, in the path of a coil. This helped reduce the blue spark from EMF.

A blue spark does not necessarily indicate that there is a bad coil somewhere. Many solenoid coils draw enough current (and form enough of a magnetic field) to create a spark under the right conditions. In fact switch contacts in solenoid coil circuits are often much bigger than switch contacts in relay coil circuits to better handle the higher current and occasional sparks.

For more background: https://pinside.com/pinball/forum/topic/dremmel-for-contacts#post-4235465

I suspect that there may be an issue behind the problem described at the beginning of this topic but not all sparks indicate problems.

I agree Mark. I don’t like the characterization of it as a big blue spark (which is common in many cases). But I’m specifically referring to the phenomenon the original poster is describing on a stepper disc. I have seen this be significant enough to cause smoke and sometimes an arc.

No theory needed! Just observation of which specific contacts are giving you the problem and then determine what is in that control circuit.

Trouble is where you find it and it’s not always where the symptoms are!

Without seeing a picture of actual unit, I was just curious; was the stepper board totally clean before the new lubricant etc?

I was wondering if there was possibly a bunch of old graphite lubricant used in it at one point, and still on it.

Just curious if a higher current running across could cause something like that.

I'm probably way off base, in this instance. Just something I had in my head.

Do you have any little holes burnt thru board or contacts?

Do your six award relays fire as the arrow spins? That would confirm whether there's current running through the wiper as it spins. I think the Delay relays should block the current until after the arrow stops.

This confused me until I revisited the schematic and found a 2nd Spin Unit wiper that drives the Delay relays:
Jive Time Spin Unit 2 (resized).jpg
The Spin Unit wiper in red in the upper part of the schematic drives the various bonus relays and is not part of an active circuit until the Score Motor, Spin Unit motor and the arrow stops. So that wiper carries no current while it moves.

The wiper in red in the lower part of the schematic drives the two Delay relays used to disable the circuit in the upper part. This wiper is live as it rotates and can heat up or arc as the wiper leaves the pad and breaks the connection. That's the short answer.

The long answer is that the most of the time the lower wiper will either do nothing, or it will activate one of the Delay relays. Activating a relay probably isn't a problem since the current going through the wiper will ramp up from nothing. Once a Delay relay is activated it closes its own lock in switch which keeps current flowing through the relay coil. So even if the wiper moves off the contact while the Delay relay is active there is no interruption in current because the lock in and Score Motor switches supply all the current that's needed. If the wiper moves on or off a contact while the Delay relay is already active and the lock in path is available the current through the wiper is negligible.

Once every half Score Motor turn though the Make/Break Score Motor switch opens which breaks the lock in circuit to the Delay relay. If the Spin Unit wiper is not on one of the contacts that can keep the Delay relay active the current through the Delay relay coil has nowhere to go so it piles up on one side of the Score Motor switch. If there's enough current it might spark although most relay coils won't draw enough current to do that.

If the Score Motor switch breaks the lock in circuit while the wiper is on a contact that keeps the Delay relay coil active there is no interruption in current to the Delay relay. If you're lucky the Score Motor switch will close again before the Spin Unit wiper moves off the contact to continue providing current to the Delay relay coil. The Spin Unit wiper effectively just carries the current briefly while the Score Motor switch opens momentarily.

The case you're seeing where the Spin Unit wiper moves off the contact and heats up is likely the case where the Score Motor switch has opened, blocking the lock in circuit path to the Delay relay, and the Spin Unit wiper moves off the contact before the Score Motor switch closes again. In this case the Spin Unit wiper is the last circuit to break, cutting off current to the Delay relay coil. But the current through a coil can't change instantly. So the current through the coil will keep flowing for a brief period and will try to force its way through any path it can find. In this case it's through the very edge of the board contact and the tip of the wiper contact and possibly through any conductive material that has been dragged out onto the board between contacts. The current flowing through the higher resistance path generates heat which fries your grease and the board.

When you observe the glow and smoke, does a Delay relay drop out briefly? I don't know the relative speeds of the Score Motor and the Spin Motor so it's hard to know how often this happens but I suspect it's not every time the Spin Unit fires up.

The designer Norm Clark prevented most of the ways this edge heating might occur by disabling the upper wiper in the schematic above as the Spin Unit rotates. He further reduced the effects the remaining ways this could happen might have in the lower wiper by picking higher resistance (lower current) coils for the Delay relays. What remained was probably determined to be a small enough problem that it wouldn't be an issue over the expected life of the game.