Switch guarantees that no extra points are awarded. In 4p games, score is everything. Tilt disqualifies ball.

All depends on what state the machine is in when the game tilts. Most of the time it'll be fine. Sometimes, there's a chance that the relay losing power will be in the process of moving the reel.

Wait, just looked up the schematic... how? You have multiple switches in the tilt relay misadjusted for this to happen.

P.S. Have you tried adjusting it properly?

Why would that cause a problem? The game doesn't care about the position of the reels... (mostly).

Oh, yeah! (burn) Well, here's a question for you: where does that other switch pair sink to, and what happens when you have power jumped to it?

I don't think so...
I'm talking about Grey-Blue 3. This is the opposite side of the SPDT of the tilt switch in question. This is the third use of that wire in the schematic - they are not connected to the other two uses.

Where does that wire go? You're switching the common under that section. Has to go somewhere. The answer likely lies in that switch.

I agree with not heavily bending and tagging the wire as a mod. Makes it easier to adjust properly later.

Nope, I'm workin'. But you have the game and a meter. I will suggest that it runs through a JP since it has to reach back up to that panel - look near the other switch on the female side of the plugs. It might change color through the plug.

Regardless, they wouldn't have put in a SPDT switch (and wired it) unless that other side was doing something. As with most SPDT switches, they don't expect BOTH sides to make contact at once with the traveling leaf. Not pushing to /dev/null. It's going somewhere.

Thanks Rolf - in this case it wouldn't matter if both sides were energized (except for the additional power drag).

Oh, was your switch dirty? Why grind the contacts or sand them with your metal wheel (did anyone mention doing that)? Why not just adjust the switch?

Just curious...

Assuming you discount the little physics note I put up there about preventing score from incrementing immediately, the other purpose may have been to spread the load of the tilt relay. Otherwise the enabling would have happened through a single switch pair.

Question for you - what happens with and without your mod when a score reel coil is detached on one side (and cannot move)?

The answer is you are still vulnerable.

Sure thing - your game, your mod, go for it. I would rather fix the problem. We are taking different approaches to the same problem, that's all. Get some rest!

OK, I'll bite:
It resolves one failure condition and does not protect against the other. The switches are not in the game for no reason.

Yes, the fact that you can burn multiple coils is a problem. How would you design around plugs? Similar issue. You're addressing a symptom and not looking at the wider issue. The real issue, in my mind, is that the relay is not adjusted properly. The tilt and game over relays on Williams games are of incredible importance. So much of the games' logic runs through there. Similarly, the 0-9 unit. Your switch can be as shiny as a mirror and still not function - you've started to ask why that might be.

And yes, I am a giant originality stickler. That's why I've poured so many hours into making the Multi play as accurately as possible.

I'm one of the precious few that like the Bally plug design. (mostly)

Thank you! Also, I'm not certain either, which is part of my problem with blocking that circuit.

Operators -did- provide feedback about game issues and their notes were incorporated later. See: bingos. Same thing happened for flipper games.

A game is no good if it catches on fire.

I have problems with plugs from all manufacturers. Bally is the only one that gives multiple points of contact to allow for a very nice electrical connection.

Other manufacturers had better mechanical connection, but there's nothing inherently wrong with Bally's plug design, other than that the metal tab bends can break easily if you are rough with the plug. Sorry, ymmv, yadda yadda.

Yes, this seems proactive. But now there is no way to cut power to all the reels at once. I'm not saying it's 100% a bad idea... I'm only asking that we think this through.

The hardest thing (for me) is to think through the ramifications of changing a circuit like this. How can it fail now?

Fusing it would actually be a better mod, from a functionality standpoint.

Their fuse holders are indefensible. Some modern ones are similar and always make me cringe as well...

Their sockets are only mostly bad, but they are easy to install, at least, especially in tight spaces.

But if you have old plugs I will definitely take them all (I use them in new game builds - yep, I find them that nice to work with).

You're still not addressing plug failure. Fuses would be a better mod, and not installed under playfield.

Also probably impacts a subset of the seven. I counted seven yesterday... But the game has to hit each of the points relays to do that. Possible.

But again, your game, do what you will.

Or the plugs on the motherboard. You are doing a quick fix, which is fine, I guess, but the problem is actually deeper if you feel that that switch should not be. You have to rewire the game, not just close the switch.

The feed runs through the bottom board, then up through male plugs - you want to eliminate the problem, correct?

You've just transferred it.

Despite the hurricane evidence, I've certainly had all manner of Williams plug failures. Cold solder joints being a thing, broken wires in and under the plugs causing intermittent contact, and crud on the legs preventing contact. Each of these is a failure point for the same problem that you're trying to resolve.

When really - the problem is the score relays. Each one drives the chimes and the reels. If the score relay is held on too long, blow a fuse rather than burn a coil. See again: bingo mixer latch coils. I know I sound like a broken record, but I really dislike (that type of - jumper insertion) changes to the wiring. I spend a lot of time fixing well-intentioned (or not so well-intentioned) changes.

That's what you're doing, you're only doing part of it.

Closing that switch does provide a hint of less coil burn. But only that. You are assuming that the rest of the circuit is similarly fine. Multiple failure points. You just found the end of the chain. My point is that you have to rewire the game (remove the switch entirely, including the travels up and down the game) to take that failure point out completely. Again, this is your game, do as you please - my notes are only to complete the picture for others reading this thread.

You could jumper it in the head instead and that would be less problematic, but harder to find.

What's the missing piece between the reels for 1p, 2p and 4p games?

Correct.

Now, what happens should that unit fail to turn and the switch remains engaged? Or it only turns partially. The player units on Williams games use these large conductive areas on the stepper itself. What could that switch be doing with regard to the player unit?

This returns to one of my earliest points about none of us understanding the purpose of that circuit at a glance and the potential danger of bypassing it without understanding. Vast majority of the time it's probably fine to bypass, much like the switch in normal operation...

Could the player unit itself burn? I dunno. I find it unlikely, but that's one of the only other things in the circuit, and something that hasn't been addressed at all in the comments thus far (that I remember). Williams player units have snowshoes (good for wicking), and big traces... not that they should be getting more than 24V, but if the unit is misadjusted and 24V goes to the wrong place, I suppose the worst that would happen is some blown out bulbs.

That switch you're bypassing has a job to do as well. (We just don't understand fully what the job is, or, if we do, it seems to serve no purpose, and the defense of a copy/paste mistake doesn't carry a lot of weight, nor the claim that the 'bean counters' would ignore it forever...). Neither of us needs to leave convinced of the others' position, of course.

Hopefully he doesn't take my discussion of the problem as criticism. That is certainly not my intent. I just enjoy these kind of puzzles and thinking a problem like this through.

I'm talking about a different failure condition - one that falls outside the bounds of normal operation - in concert with this other failure condition. I agree, when the unit is built up and operating as it should, you don't see excessive carbon tracking or burns... but it certainly could if adjusted incorrectly. Drawing double the amount of current through a smaller surface area.

That's fine - I think, though, that more examination on the purpose of that switch in the games might be useful. I apologize that I haven't had time to do more research myself, but finding the changeover game (which someone else may have posted) would be helpful - then finding the 4P game prior to. That would likely help figure out why the switch was added. And there was some kinda reason at one point in time. Reviewing both schematics should help clarify. I suspect it's not a mistake - I'm just too dense to figure out why not... yet.

Bingos are the best! Fun games, super easy to work on, and lots of fun puzzles. Speaking of, I hope to get down there soon! Join me....

Thanks JR - I don't know about the rest of that quote (as pertains to me), but I feel the same way about you.

OK Nic - I think I've solved one mystery, spent a couple of mins reviewing schems:

The purpose of the switch is to prevent erroneous award of EB as designed in A-Go-Go. It blocks the EB relay if not already active through the score drums.

Somewhere between A-Go-Go and Fan-Tas-Tic (quite a few games in the middle), the designers re-drew the EB award/replay award circuit, but it's still doing the same thing - it's just more clear on A-Go-Go's schem because of the old style adjustment jack and placement of the EB relay right beside that circuit.

Keeping that switch closed will allow awards to be earned based on position of the reels even though the game should not allow them to do so. It's a failsafe for the OTHER tilt switch failing. I'm always open to another interpretation, but there's mine.

The engineers did have a purpose for the switch, and, to distill it to its essence, it is to prevent cheating. As with most anti-cheat circuits, they are not readily apparent (at least to me).

Smoke can come out of these games for multiple reasons, as with all pinball, and there's not a way to prevent all of it. As I've mentioned, you are pushing the smokestack further back into the game, but it's still there. Jumpering the male side of the JP would be a more obvious/safer way to change the game. Fuses better still.

I wrote that off for that reason as well - but I'm back to my order of operations theory on the one hand, on the other, perhaps if that switch on the 1000pt relay is misadjusted... I think they were engineering around a possible malfunction elsewhere in the machine and were erring on the side of less payout.

Well if that were the case, the game would smoke for a different reason, now that I think of it. Not in normal operation, but in tilt, and only with your mod...

Only requires one switch on the relay to fail. Those relays are exercised more than any other in the game.

Also, the problem would only appear on replay or eb award.

Sure, but only in your scenario will a coil burn. I guess both scenarios.

Do you disable replay award in the museum? How about eb? What about match? Match should be ok, would need to check.

Only 4p? Again, you have different units that you run through on a 4p game. Player unit and 4x score reels which allow for replay or eb award. Yes, it's based on position of that unit. Thinking like a cheater, player unit is kinda accessible with a coat hanger for Williams games, huh? Push with the hanger and you can bridge multiple steps easily. Might tingle a bit without tape.

Sounds like you're stuck in on this, so we will have to agree to disagree. There is a purpose to that switch. It cuts off the score relay switch in question when tilted. Also, the replay award calculation circuit.

I don't understand your last question... during the non-tilted portion? When the reels are active, perhaps you hit the replay value as you tilt. As designed, you don't get your credit. As modified, you get your credit, then the replay circuit locks on. Ditto for trip relay for eb, if trip or hold. You're safer to use eb award vs replay with this change.

You can ignore it if you choose, your game, etc. I won't say 'at your peril' because your change is relatively harmless. I don't think it needs an apb. But that's my opinion.

There is a downside, but I've given several possibilities. Other issue might be related to ebs. Don't know if big chief had ebs or not.

If that is the justification, often enough to justify adding a switch.

You underestimate how the machines can be abused. Lift the front legs. No drain! Coil locked. I agree, you'd have other problems then. I'd suspect you have other problems if that NC switch wasn't working too. the coat hanger is a multipurpose tool. It can also push reels...

Eb is safer because it is via a relay meant to hold on. Not so with credit.

Yes, it could and would - in both cases - EB has to hold so that you are allowed to play your EB. It is unaffected by tilt. If you got it, you got it.

Same for credits. They are -normally- affected by tilt. Momentary pulse of the stepper is cut off. You're leaving that path active, and forcing it so. I'd have to check and see if there's a switch on the credit unit that is unaffected that would cut power to the coil on step... can't remember off the top of my head.

No cut-off switch on the credit stepper - just bzzzzzzzzz - unless you have your game modified for free play in the typical williams fashion - then you are safe from this particular issue on credit award. Of course, that wasn't contemplated when the games were new.

Really? The schematic shows that the score relays allow it to remain... 3 NC switches and a hold switch on the relay itself. Yes, the ball index switch cuts it off, but only when the ball index drops... due to score. Unless my super-quick read of the schem is wrong - which it very well could be.

More importantly, the Red... haha - I was reading past that to the award circuit, not the hold circuit. The ball index relay doesn't even come into play on a tilt.

I'm with CactusJack that it must've been too taxing to put it all on one switch. Would probably draw a nice big spark. And without ending the game, it could happen on every ball. Of every player.

Rolf: Working back from the EB relay, the most important thing to note is not the ball index relay, it's the other tilt relay switch which cuts off power to most of the game. I just meant I made a mistake and ignored that important switch. Cutting off power to the ball index is a supplemental way to cut off power to the EB relay, if there is scoring happening at the same time.

Proof that one should not interpret schematics and work at the same time.

Yeah, I agree it's the same switch since there would otherwise have to be two SPDT switches with the Grey-Blu 3 wire jumpered across, and the manual doesn't show that. Just a convenience thing if you have a ball index relay issue.

--Edit-- oh, now I understand what I meant - I meant as far as the EB relay holding power goes - the ball index doesn't enter into the equation because the hot wire is completely removed from the EB relay by the tilt relay switch.