It looks like the 10 pt drum unit is only fired by the 10 pt relay, and the 10 pt relay is only fired by the advance relay. Are either of those 2 relays - the 10 pt relay or the advance relay - stuck on?

If not, there are a few things that activate the advance relay (see snippet below): the L & R top rollover sw's, a sw. on the No 2 bumper relay, and EOS sw. on the advance relay, and whichever rollover button switch is connected through the advance unit. Are any of those switches stuck on or shorted?

Paddock problem (resized).JPG

It looks like what breaks the circuit once the advance relay is activated is an EOS switch on the advance unit that's in series with its lock-in switch. If you can find the advance unit, see if that EOS switch is working. It should be a normally closed switch that will open once the advance unit plunger is pulled all the way in.

Did you check these four switches to see if any of them are stuck? Only thing on the playfield that scores 10 points, except the pops when lit.

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I suppose you could have a short that's not obvious somewhere in that 10 pt drum reel circuit. At least if the 10pt relay and Advance relay are not locking on, and the EOS switch on the advance relay is good, then you've eliminated those relays and all the switches that activate them.

I wonder if your unsoldered both ends of the O-W wire that runs between the 10pt relay and the 10pt drum unit, then used a jumper wire between those two points - if it solved the problem, you'd know the short is somewhere in that stretch of wiring...and if it doesn't solve it, then you know it's somewhere else.

Shorts like that are hard to find. Maybe you could unsolder both lugs of the 10pt drum unit solenoid and put a light bulb (2 12V car bulbs in series if you have that around) in place of the solenoid. That way you could leave it on without the risk of burning up the coil. You'd have a light burning while you wiggle wiring harnesses and poke around (carefully, of course)...you could see if the light blinked off for a moment if you're close to the problem.

I'm just trying to think of some way to narrow down the area where the short could be.

Paddock/Post Time was the First Pinball machine with 3” Flippers at the bottom. They never had 2” flippers installed.

How much space do you have on the first contact nearest to the 10 point relay?
If the gap is to narrow it will pull in by itself.

Also check that the EOS switch on 10pt unit opens correctly when unit solenoid pulls in.

Could the switch on the 10pt relay be shorted? According to the schematic, that's the only switch in series with the D.U. coil, so if you are using a jumper to bypass everything between the 2, and the D.U. coil still energizes when you connect the jumper, the short must be through the 10pt relay switch. Look at that relay very closely....touching tabs, solder splashes, wires touching anywhere.... Look at that middle switch - O-W and Y wires. See if it measures a short between the switch tabs.

I was confused by what you wrote earlier - you said it scored correctly when you were running a jumper between those same two points?

10 pt relay (resized).JPG

You started the post stating that the coil energized as soon as you connected the jumper that effectively replaces the O-W wire. Did I understand that correctly? So the D.U. coil energized - does it stay turned on? If not, when does it turn off?

Sorry...I'm still confused - so the 10pt D.U. stays energized, but you're able to start a game with the D.U. locked on like that, and the machine is scoring correctly? Just not resetting correctly?

Do you have a multimeter? I'm still curious if you have a dead short between the 2 tabs on the back of that 10pt relay switch.

Based on the latest experiment, it sounds to me that the problem lies in the reset path, not the scoring path. There should be 2 wires going to the 10 point score reel coil. Look carefully at the reset wires that go through the zero switch. I attached a screen shot of that portion of the schematic with a yellow highlighted path. One detail that I find interesting is that the 10 point reel is the only one that doesn’t gate the reset pulses by a dedicated switch in the reset relay. So, if the B-BLU wire gets shorted to yellow, you’re going to see the problem that you describe.

Good luck,
Dave

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Hi dgAmpGuy - thanks for that observation - makes sense, except that (if I'm understanding correctly) the op has disconnected the O-W wire from between the 10pt relay sw. and the left lug on the 10pt D.U. coil. - replacing it with a jumper, and the D.U. coil still fires. Doesn't that remove the whole reset circuit from the equation?

Thanks for the video. When you touch the lug of the D.U. coil with the wire that you unsoldered from it, you're still connecting the D.U. coil through the reset circuit that dgAmpGuy highlighted in yellow. You're disconnected from the 10pt relay switch, so that's out of the picture, but as you say, your problem is with either that D.U. switch that's supposed to be open at "0", the motor impulse switch, or the make/break switch on the reset relay - those switches highlighted in yellow in post #22.

You're narrowing it down!

Ok. I see two wires connect to each other at the reel. One of those wires goes to the 10 pt relay. The other wire goes to the circuit that I highlighted. That’s what you need to figure out.

One tool that I have found useful is connecting two 12 volt car bulbs in series and putting 2 long wires with alligator clips on them from each of the other 2 bulb terminals. This allows you to hook into the 24 volt circuit and observe the pulses (or steady state) of the various points in the circuit.

If my paddock was doing what yours is, I’d connect one side of the light tester to black, then move the other side through the path that I highlighted, from left to right, starting at the reset relay.

Dave

I don’t think the problem is with the relay. You are touching two wires onto the score reel. Separate them and try again. I bet the relay wire is fine. It the other wire you need to follow.

That B-BLU wire shouldn't be hot unless the make/break switch on the reset relay AND the Impulse-A switch are both closed. Since they're in series, if only one was shorted, that B-BLU wire still wouldn't be hot unless the other closed. You could unsolder a wire from each switch and see if the switch is shorted (be aware that using a meter doesn't work all that well on EM's unless you unsolder one side of the switch because of parallel circuitry that can affect the reading). But the chance of both of those switches being shorted is pretty small. I suspect a short in the wiring somewhere between the left side of the reset relay switch and the right side of the impulse-a switch (between the YELLOW wire and the B-BLU wire), effectively bypassing both those switches and keeping that B-BLU wire hot. I hate trying to find those kind of shorts - you may have to unwrap some wire bundles and trace those wires carefully. Once you've eliminated those 2 switches as the source of the short, that's all you have left, I think.

Paddock (resized).JPG

Please define what you mean by “hot”?

Do you mean connected to yellow or connected to black?
If you connect your test light to yellow and then black-blue, it lights when 1000 or 100 goes non-zero? This is expected because you’re getting a circuit through the drum up coils.

If you connect your test light to black, then to black-blue is it on after reset completes and 1000 or 100 are non-zero? This shouldn’t happen because the non zero switches only connect to black through the drum coil.

You should be able to isolate it to a wire between 2 points, then it might be as paulace said and it’s a short in the cable run.

Edited to fix boo boos and clarify.

Dave

I'm sorry if I confused the issue using the word "hot". dgAmpGuy is right, since we're talking about AC from a transformer, there's not really a ground, just a return, and so everything is relative to some reference point. So let's take your light bulb tester (a handy tool on EM's...glad you made that). You could use a meter as well set to AC voltage, but the lights will work just as well since we're just looking for the lights to be on or off. The important thing to remember is that if you clip one side of your lights to the right lug of the 10pt coil (which is essentially the BLACK wire), then any voltage we're talking about is relative to that BLACK wire....so let's take that as our reference.

If you then hook the other lead of your test bulbs to the YELLOW wire (where the purple "X" is), your bulb will always light because you're putting 24V across the bulb. If your lead is connected anywhere else, and the light comes on, it means that you have a connection to the YELLOW wire though whatever switches are involved....that is, those switches between the YELLOW wire and wherever your test lead is connected are closed.

Hooking the other lead of your tester to where the green or blue "X"'s are should be more informative:

- If you're hooked to the green "X", the light should come on when the reset relay make/break switch changes state from how it's drawn. (That is, the lower switch on the schematic is closed)

- If you're hooked to the blue "X", the light should come on when both the reset relay make/break lower switch is closed, AND the impulse switch is closed. So during reset, as the score motor turns, the light should rapidly blink on and off as that impulse switch A opens and closes. Once the reset is finished, the bulb should be off as both the reset make/break and impulse switches are open.

So I'm curious to see - setting all the drum units to zero and turning on the game - if you connect the other clip of your bulb tester to anywhere along the B-BLU wire (where the blue "X" is), does the light come on? It shouldn't. At that point, the reset relay make/break switch should be open, as shown. Also, if the score motor is in the home position, the impulse A switch should also be open. Your light should only come on if those two switches are both closed. (Remember, that's assuming the other lead of your light tester is attached to the BLACK wire.)

I hope this wasn't talking down to anyone - just wanted to make sure we're all talking about the same thing.

Paddock reset circuit (resized).JPG

The light is off when your leads are connected between the BLACK and YELLOW (purple X) wires?

Yeah, if you wouldn't mind, check that again. Make sure one lead is on the lug of any drum unit coil that has a black wire attached to it, and the other is on the yellow wire connected to the make/break switch on the reset relay. If hooked between those 2 points, the light should be on.

If by C-8, you mean where the switch is located on the schematic, then yes. Physically, it'll be the switch highlighted in this picture....the yellow wire in the center of that center switch 2B.

Paddock reset relay (resized).JPG

To clarify, OP is talking about the switch paulace hilighted. He's referring to the column there that specifies the switch location on the schematic.

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Thanks HowardR - hey, since you're watching, if you see me saying anything incorrect, feel free to step in and straighten me out.

Hi Tonup69 - So I'm not understanding this - if I connect a light across the yellow and black wires, which is straight across the 2 voltage "buses", wouldn't the light turn on? There are no switches involved in that path, just the light across 2 terminals? Hope I haven't been steering the poor guy wrong! *laugh*

I guess for this example, we could think of the yellow and black wires as the two terminals of a battery. (It's just a battery that switches current direction 120 times a second.) All we're doing is connecting a light bulb across the two battery terminals - won't it light?

Sorry Tonup69 - I misread your earlier post - had to erase my last one. Just ignore that one.

Ha- good! If you can wire up a motorcycle, you can teach me about electrical stuff, then! Someone needs to! *laugh* Still looking over your results....trying to make sense of them.

Well, I'll try to run through how I think the reset circuit works - see if this makes sense. Let's assume when you turn the machine on, all the drum units are at "1".....not at zero, so all those drum unit switches that are open at zero are now closed:

So when the machine resets, the reset relay is energized
- this switches the make/break switch just to the right of the purple X on the snippet on post #33, closing the bottom switch, and also closing those 3 reset relay switches that are in series with the D.U. open at zero switches.
- the score motor also gets a signal to rotate from the reset relay and starts to move
- the impulse switch closes 5 times as the score motor rotates half a turn

- since those 4 D.U. open at zero switches are all closed (the score reels are at 1) and the reset relay switches in series with them are also closed, those 5 closures of the impulse switch complete a connection to each drum unit and makes each coil fire 5 times.

- this continues until the score reels read "0", at which point, the D.U. open at zero switches open, which blocks the pulses from the impulse motor switch, so the reels stop turning. They now sit at "0".

- When the score reels all read zero, the reset relay relaxes (not sure just how that happens yet), which stops telling the score motor to turn and returns that make/break relay switch near the purple X to the state as it's drawn.

Hopefully that makes sense, and if anyone sees anything wrong in that, please chime in.

I don't understand why the 10pt reset circuit is the only one without a reset relay switch in it....maybe someone could explain that to us.

I'm looking at your previous post #44, trying to make sense of it. So the first thing you noticed - light is on when connected to purple X makes sense....the light should be on no matter what state any of the switches are in. So that's good.

The second about the green X - if the reset relay is not energized, and therefore the make/break switch is as drawn, then the light should be off no matter what the impulse-A switch and drum units zero switches are doing....so there's a problem there. It's acting as if the make/break switch on the reset relay is closed. So there's got to be a short somewhere between the purple and green X's. If that's true, then your observation makes sense.