I have a weak upper right flipper on my BK2K, and was wondering if there's a way to verify that before swapping it out with another coil of the same kind. When I say "weak flipper" I mean that I can hold the flipper in place when pressing the button with a minimal amount of force. The same amount of force knocks my finger away with the other two flippers. This is more than just a less-than optimal plunger travel path. I just got this machine, and it looks like the plunger and link assembly is new, but I can't tell about the coil. I've tested the voltage to the coil and it clocks in at about 70 volts.

I have a spare flipper assembly with the right coil type from another System 11, but I'm just curious if there's a way to know for sure if the coil's the problem without having to take apart the flipper assembly twice (once for the coil and once for the known good plunger/link assembly". I suppose the problem could also be the EOS switch. Maybe it's in bad enough shape that the flipper never gets the full kick it needs.

Any helpful testing tips, or do I just have to do this the hard way to isolate the problem?

It is! One of the pop bumpers had a switch that was just a bit too close together, so would lock on and blow a fuse. I fixed that up, so all I need to do now is fix this weak flipper and it'll play great until I get around to really cleaning it up and/or selling it. But that's way down the line.

I tried replacing the plunger and coil sleeve first, but no luck. I tried replacing the coil, but still no luck. That leaves the EOS switch blocking the high-power part of the coil from getting a full kick, I suppose. I've tried clamping it tightly closed to see if that gives it anymore kick (like Vid tried in his flipper rebuild guide) but that didn't work.

This is the type of flipper assembly that has a capacitor on it. Is that something that could affect flipper performance?

The bushing is about the only thing I haven't tried messing with. Here's where things stand:

~70 Volts at the coil
Coil swapped with known good
EOS/Capacitor swapped with known good
Plunger/link swapped with known good

I haven't done much with the cabinet switch other than try to clean it out. It's a single leaf switch, and the lower right flipper kicks like a mule, so I need to consult the schematic to see how a single leaf switch drives both flippers.

I suppose I could shotgun it and replace ALL THE THINGS, but I'm really trying to work on my "isolate the problem" skills instead of falling back on the Giant Sledgehammer approach.

When I press the flipper button, I'm able to hold the upper right flipper down with my finger with a relatively small amount of force. The amount of kick the flipper delvers is just barely able to get the ball up into the drawbridge ramp, and/or around the loop with any kind of force. If pressing the flipper button partially in makes the lower right flipper stay in, I don't know how this is done, since there's only a single leaf switch at the flipper button, and no amount of partial press makes one flip without the other one.

Also, cleaning the contacts with a business card doesn't work, since these are high powered switches, as Lloyd says above.

Well, I give up. I've moved the coil, sleeve, plunger, spring and EOS/capacitor from the lower left to the upper right and nothing has changed. There's nothing wrong with the bushing, as the flipper bat turns freely with the slightest push when the it's just sitting in there by itself.

I guess I just have to deal with a weak upper right flipper. I've been able to figure out just the right angle of attack on the ball to get it up and around the loop a decent percent of the time, but the flipper just can't get the ball up into the drawbridge unless the angle is perfect and the ball is moving just the right amount of speed going into the flipper. Compared to videos I've seen on YouTube, I feel like I'm playing this game on hard mode.

I've tried as much as I can without ordering a complete flipper rebuild kit. I guess I'm going to have to wait until it's time to rebuild this thing before I can have a fully working game.

Thanks for your help, everyone!

It's a parallel coil, so we've got power on the thick/thin lug, return on the thin lug and EOS on the thick and thick/thin lug. Unless the EOS was wired wrong, wiring it backwards wouldn't have much of an effect, would it?

It looks like I misspoke earlier about the wiring. Here's the wiring as it currently stands:

IMG_2417.JPG

(I've since cleaned up the black/yellow wire's solder join to give it more contact)

It looks like power is on the thick/thin lug on the left, the return is on the thin lug on the right, and the EOS is on the middle and right lugs, as Vid describes in his Flipper Rebuild thread:

402375.jpg

https://pinside.com/pinball/forum/topic/vids-guide-to-upgradingrebuilding-flippers/page/18#post-2440011

The hold voltage seems fine. It takes about the same amount of force to break the hold voltage on all three flipper. The difference is that the lower two really fight me when I do that, but the upper one just gets mushy.

Something that's weird is that the manual's wiring diagrams don't line up with reality. The manual describes an upper left flipper that doesn't exist, and the wire colors don't seem to match.

Something else I found is that the upper right flipper appears to get its return to ground from the lower right flipper. Next to the EOS switch on the lower right flipper is a second leaf switch that activates the upper right flipper, but only when the flipper button is pressed. It's possible that the return to ground through the lower right flipper isn't enough to get a real kick out of the upper right flipper, but the upper right flipper measures a strong 70 volts, and the upper flipper is wired correctly (as far as I can tell). I seriously have no idea what else I can check.

Are the flippers controlled by transistors? That seems odd for a non-Fliptronic style game. I thought the flippers existed outside of the special solenoid setup.

How does a blown fuse cause a flipper to be weak? Wouldn't that cause the flipper(s) to not work at all? I'm just wondering if there's some kind of wiring that I'm not aware of in my BK2K that wasn't present in earlier System 11 games like Pin*Bot, Road Kings or Taxi.

I see that LTG was still signing his posts back in 2005.

I'm still curious, though, about how a blown fuse would cause performance to drop rather than just stop altogether. Would said fuse be wired in parallel with another, higher-resistance circuit?

OK, that makes sense. I'll check all the fuses again, though I'm not sure that's the problem. Only one of the three flippers and none of the other solenoids are having problem.

Yep. And all the flipper coils report a nice steady 70 volts when measured to ground. So unless the problem is on the return side, the problem isn't electrical.

As I mentioned before, there's nothing wrong with the bushing. When the flipper bat is in there by itself it spins freely with little to no force, no different than the other two flippers.

As I mentioned before, I've already replaced the coil with a known good one. Two, actually - one from another machine and one from this one. No luck.

EOS errors aren't really a thing with System 11B. Bypassing the EOS to see if the "kick" returns to the flipper doesn't really help.

Sure. But if I remove the EOS from the equation altogether by connecting the two tabs on the switch together with alligator clamps and a wire, the problem persists.

I've replaced the coil sleeve, the plunger/link assembly, and the return spring. The bushing is fine, though I suppose I could try replacing that. I'm not sure what else there is to replace. Eliminating all the mechanical issues leaves the electrical issues, and eliminating all the electrical issues leaves the mechanical ones.

It's update time! I might be grasping at straws, here, but I suspect these coils are wired wrong.

THE LOWER-RIGHT FLIPPER

Coming from the right flipper button is a blue-violet wire. This wire goes into the thing-wire lug on the bottom-right flipper coil. An EOS switch wire comes out of that lug, and the other EOS switch wire goes into the middle thick-wire lug. A gray-yellow wire comes out of the double-wire lug.

LowerRight.JPG

THE UPPER-RIGHT FLIPPER

Also coming from the right flipper button is a black-yellow wire. This wire goes into the thin-wire lug on the upper-right flipper coil. An EOS switch wire comes out of that lug, and the other EOS switch wire goes into the middle thick-wire lug. A blue-yellow wire comes out of the double-wire lug.

UpperRight.JPG

THE BLUE-YELLOW WIRE

The blue-yellow wire that comes out of the double-wire lug on the upper-right flipper goes into the middle thick-wire lug on the lower-right flipper. I have no idea how to reconcile this with the cabinet wiring diagram.

Wiring.jpg

First off, there's no "upper-left flipper button". There's not even an upper-left flipper. Let's assume that's a typo, and that they mean "upper-right" flipper every time they say "upper-left". There's a blue-yellow wire that comes out of "flipper power" and goes into "flipper coils" but that wire disappears in the schematic. I see that there's a dotted line between the "upper-left" and "lower-left" flippers. If we assume that the "upper-left flipper" label is a typo, could that dotted line represent the blue-yellow wire that goes between the lower-right and upper-right flippers? Let's assume that it is, for now.

Something of note is that the upper-right flipper coil will only ever fire if the lower-right flipper hasn't opened its EOS yet. Is that normal? Could this be related to the blue-yellow wire? Is it possible that blue-yellow wire is misplaced on one of these coils?

OK, so it turns out that the blue-yellow wire on the lower-right flipper, doesn't actually go right to the upper-right. I was completely wrong. The lower-right flipper's blue-yellow wire goes to a switch right next to the EOS swtich.

SecondSwitch.JPG

A solid blue wire comes out of that switch and goes off to a weird auxiliary board.

WeirdBoard.JPG

This switch presumably helps drive the upper-right flipper. I tested connectivity on this switch, and regardless of whether it's open or closed, it shows connectivity. The same goes for the EOS switch above it. Connectivity between the two leafs, regardless of whether they're open or closed. The EOS switch on the left flipper doesn't do this, though.

God, this whole thing is blowing my mind. I really need to get familiar with how lower and upper flippers are wired in a System 11. Is there anyone that can help me make sense of this mess?

Also, it looks like the varistor (thermistor?) on the right flipper button leaf switch is broken. I presumably need to replace it. What are the specs on it?

Correct. There is one leaf switch at the button. It looks like the lower-right flipper has a leaf switch under it that closes when the EOS switch opens. Pressing this second switch closed by itself (without pressing the flipper button) doesn't do anything, and I can't really test if the EOS switch needs to be open for the upper flipper to work without burning the coil out, I think. I suppose I could take the flipper bat out, press the button and see if the upper flipper actuates when I manually close that second leaf switch while keeping the EOS closed. But what would that show me?

I've measured the voltage at the upper-right coil, and it comes in clean at 70 volts. That's means there's nothing impeding current flow before that point. But it looks like there's tons of stuff between the coil and ground that could be impeding flow, and I just need to find out what it is.

That'd be 100 nF or 100,000 pF, correct? Can I get one rated at a higher voltage, like, say 1000 volts? If not, then are they pretty standard across System 11 games? Could I pull one from, say, a Taxi?

I'm asking if a higher voltage is OK because I don't have an order to place at GPE any time soon and I have a big ol' electronic component store ten minutes away. They don't sell a .1 uF capacitor at 500 volts, though.

EDIT: Looks like it is.

http://www.niccomp.com/help/capsubguide.asp

The one at the local store is a higher-rated voltage, and actually has a better-rated capacitance change than the one at GPE. Excellent. I know it's not required, but I may as well pick one up next time I'm nearby.

http://www.radio-electronics.com/info/data/capacitor/ceramic-capacitor.php

http://www.vetco.net/catalog/product_info.php?cPath=114_116_633&products_id=13804

Excellent. With that relatively minor detail out of the way, time to delve back into why this flipper is still so weak.

I'm not sure what you mean by coil stop bracket. Do you mean the L-shaped part of the coil stop that the cylinder itself is part of? Can you post a picture?

Well, I once again have no idea what's wrong.

The flipper button has the ground return wires for the top and bottom right flippers on one tab and the orange wire on the other, which goes straight to ground. The bottom flipper works just fine, which means it's getting the power it needs, and its path to ground is unobstructed. The top flipper is really weak during the flip, which means it's wither not getting the power it needs or its path to ground is obstructed. Both flipper coils read 77 volts at all three lugs, so I have to assume that power isn't a problem. I put an alligator clip on the ground return lug of the upper flipper and tapped it against ground and the flipper kicks with the same power as it normally does - weakly. This means that I've eliminated the return to ground as a problem.

So what I have left is a mechanical problem - except I don't. I've replaced the plunger, the EOS switch, the coil sleeve, the bushing and the return spring. There's literally nothing else I can do to this thing.

I guess I just have a broken machine.

Well, hell. I think I just fixed it.

The blue/yellow wire that provides power to the upper flipper is daisy-chained from the lower flipper. This is presumably so they don't have to provide three power supply lines from the backbox. This daisy-chain wire comes from the middle lug on the lower flipper. Throughout this process, I've been wondering if this is the right wire to daisy chain from.

Based on what I know about how System 11 flippers work, both the high and low power coils are going at the same time during the flip. The high-power lug gets dropped from the circuit when the EOS switch opens. This leaves the low-power coil active. It seems weird to me that the power for the upper flipper would come from the lug that gets dropped right when the upper flipper gets activated. In fact, given what I just described, I have no idea how the upper flipper is even getting power when the lower flipper's high-power coil drops out.

Then I saw this in the manual:

FlipperWiring.jpg

I really think that someone hacked this thing up before I got it. Among other things I've seen, both flippers have a gray-yellow wire delivering power to them, as opposed to grey-yellow going to the left and blue-yellow going right. I have no idea what's going on. But what I do know is that the blue-yellow daisy chain wire is supposed to connect to the same lug that the coil power goes into on the lower right flipper - certainly not either of the lugs that the EOS switch is connected to, as it is in this picture:

LowerRight.JPG

Anyway, I decided that since the only thing I really had to risk was a fuse, so I moved the daisy-chain wire from the middle lug to the left lug on the lower coil. Boom. Instant difference. The ball goes up and around that skyway loop super fast and makes it into the drawbridge with no problem at all.

Is there anyone here with a BK2K or some other game with an upper flipper that can verify that this is, in fact, how it's supposed to be wired? I'd hate to think I've got it figured out and be slowly killing my flipper circuit.

Well, I haven't been able to find any pictures of a properly wired third flipper on a system 11 game, but I plugged the wiring diagram from above into the Falstad circuit simulator, and it works fine. If I move the power line in the simulator from the left lug of the coil to the middle lug, it errors out because it doesn't know what the heck to make of it. That's gotta mean something. I played three or four games in a row with this corrected wiring and everything seems to be working fine. At least, with the flippers. There's a bunch of other stuff the previous owner did a real number on. One step at a time, though.