It really sounds like the start button is stuck, but you say it is not. Next thing I'd say is a stuck coin switch which is pretty common. Unplug the coin door jones plug (inside of the main cabinet) with the game off and turn it on and see what happens. You will likely not be able to start a game but it will let you isolate the problem.

You can also check the switches that send power directly to the score motor. Check the following switches:

Top area exit relay - switch with yellow wire and red/yellow wire
Eject hole relay - switch with yellow wire and red/yellow wire
3000 point relay - switch with yellow wire and red/yellow wire
50 point relay - switch with yellow wire and red/yellow wire
Outhole relay - switch with yellow wire and red/yellow wire
Reset relay - switch with yellow wire and red/yellow wire
Coin relay - switch with yellow wire and red/yellow wire

Check the adjustment on these switches. And check the wire lugs/wires on the switches to make sure they are not touching...

Use the search here for "score motor keeps running"-very common problem usually related to score reel zero position switches and the home position switch on the score motor itself. The player issue might be related to the player stepper as a separate problem.....

There's only a few switches that send power to the coin relay coil... Check all the coin switches on the coin door. Make sure they aren't stuck in the closed position. Also check the wire lugs and wires on the coin switches...

Hi Herman
I would like to stay with @Otaku, post-2 - he suggests: UNPLUG everything from the coin-door. Doing so You cut what I show with "green X" in the JPG. I then only see (encircled red): Self-Hold-Switch*** on Coin-Relay and "Switch on Credit-Relay" - both have wire-grey, wire-blue-white on the solder-lugs.
IF (if) the Credit-Relay PULLS: The switch is entitled to be closed - question: DOES the Credit-Relay pull ?
IF (if) the Credit-Relay does NOT pull: question: Is the switch faulty closed ? So look at this switch on the Credit-Relay.
Look at the Coin-Relay --- a short wire runs from one side of the coil on the coin-relay to "Switch mounted on the relay" - the Self-Hold-Switch*** - question: Is this switch faulty closed when the relay is not pulling ?

"Encircled orange" is the Score-Motor-Switch-8 (B or C or D ?) - question - when the fault happens: DOES the Coin-Relay STEADY pull - OR does it pull-in and let-go for a moment - then pull-in etc. ? When the relay is steady pulling: Score-Motor-Switch-8 might be faulty - never opening.
Please look first at the switches on the relays --- "Only a faulty Score-Motor-Switch-8" does not make the symptoms You describe.
Please unplug again (coin-door) - and then check the relays and the switches on the relays - wait with the Score-Motor-Switch-8. Greetings Rolf

0Little-Joe-Work-01 (resized).jpg

The coin switches are at the bottom of the coin door at the bottom of the coin acceptors. They are the small dark brown/red boxes with a stiff metal wire attached to them. Also check the credit relay. Look at the switch on the credit relay with the gray wire and blue/white wire. This switch should be open when the game is on ball 1 and ready to play...

Just to confirm, when you reset the machine, all the score reels reset to zero and the score motor keeps running?

Looking at the schematic, and from your previous troubleshooting, the only switch that would be sending power to the coin relay coil would be the credit relay switch. So, this would mean power is being sent to the credit relay coil. Check the switch on the credit relay with the green/yellow wire and brown/red wire. Make sure it is adjusted properly.

Also, check the credit button switch to make sure it's operating properly...

I'd also look at the coin switches again. One of those switches might have malfunctioned internally. You can always disconnect one of the wires from the coin switch, and this will tell us if they are working properly or not. If you disconnect a wire from the coin switch, and then the score motor stops running, then the problem would be with one of the coin switches...

When you do a continuity check on a switch, you usually need to disconnect one of the wires from the switch. This is because the switch can be part of multiple circuits, which would make the switch have continuity even when the switch was open. If you disconnect a wire on an open switch, and it showed it still had continuity, then the switch most likely has a short in the switch stack...

Now we'll need to check why players are being added to the game over and over again... When the game is resetting does to total play meter keep advancing its digits?

What is sending power to the coin step up solenoid? Check the following:

Score motor switch 3B - switch with orange/black wire and white/brown wire
Coin unit relay switch - switch with yellow wire and orange/black wire (possible short in switch stack?)

I'm still suspicious about those coin switches... You can try to disconnect the coin door Jones plugs and then manually push in the reset relay to see if the machine would do a complete reset...

Here's a few more switches you can check that are in the score motor circuit:

Score motor 1E - switch with white wire and black/white wire
2nd coin chute relay - switch with white wire and red/yellow wire
3rd coin chute relay - switch with white wire and red/yellow wire

See if these switches are adjusted properly.

To perform practical troubleshooting, I would first check the switches that directly send power to the score motor. If you still haven't found the problem after that, I would then check the relays that control those switches in score motor circuit. Checking ever relay and switch on the main board isn't an efficient way of troubleshooting...

He is correct,with "efficient" being the key word. However,its the only way I know and prefer. Time consuming yes, but if you have the time you learn and discover a lot that could prevent future problems.
I use several good lights, a magnifying visor if needed, sometimes reading glasses or a handheld magnifying glass. I want to see EVERY solder joint,switch contact, wire,etc, close up.
Along the way I clean/adjust every switch as needed, service the stepper units and repair a host of issues I discover.
I do this to all the boards before hooking everything up. I have did this to 3 machines so far and they play solid and flawlessly for the most part (still a few fine-tuning issues on the last restore)
This procedure may not be for you but I believe in it if you have the time and patience.

Unfortunately, adjusting and cleaning every relay and switch on the main board might not resolve the problem if there are latent issues in the circuitry...

You've already narrowed down the problem to the main board, so I would only concentrate on the main board switches that send power to the score motor. A simple trick would be to "block" all the switches that send power to the score motor. You can just take a piece of packing tape and put tape on the switch contacts to block the power from going through the switch.

When all the related switches are blocked with tape and the score motor keeps running, then that would mean there's a short in one or more of the switches. On the other hand, if the score motor stops running, then we would know there's one or more mis-adjusted switch on the relays.

Check to see if any of these relays are on the main board:

Top area exit relay - tape between switch with yellow wire and red/yellow wire
Eject hole relay - tape between switch with yellow wire and red/yellow wire
3000 point relay - tape between switch with yellow wire and red/yellow wire
500 point relay - tape between switch with yellow wire and red/yellow wire
Outhole relay - tape between switch with yellow wire and red/yellow wire
Reset relay - tape between switch with yellow wire and red/yellow wire
Coin relay - tape between switch with yellow wire and red/yellow wire
3rd coin chute relay - tape between switch with white wire and red/yellow wire
2nd coin chute relay - tape between switch with white wire and red/yellow wire

And score motor switch 1E - - tape between switch with white wire and red/yellow wire

If any of those relays are on the main board, you can tape the related switches and then try to start a game. Then you'll know if you have a short in a switch or a mis-adjusted switch...

Hi Herman +
in post-19 You write about having the Coin-Door Jones-Plugs unplugged (and some more Jones-Plugs. also). So You have the situation "bottom of my JPG, post-10" --- my "green X" show: "unplugged". There I show "encircled red" two switches - please try: Sneak-in a stripe of paper into each switch (not yet sneak-in on Score-Motor-Switch-8) - Plug-in, toggle-on, start a game - what does the Score-Motor do ? Greetings Rolf

Hi Herman
Your snippet / text to are good, thanks. It is easyer to look in the JPG in post-10. Start on the top of the JPG - the Coin-Relay-Coil - wire-grey - down - maybe to the left, maybe to the right , down to text "tie when TWO-Coin-Unit not used" down to my green X, Also there wire-grey runs to the right - to my often mentioned Switches***. One of the switches is named in the JPG as "COIN RE." - it is the Self-Hold-Switch mounted on the Coin-Relay.

Please: ONLY look at the JPG in here (do not read the text - it is an other topic) : https://pinside.com/pinball/forum/topic/williams-big-deal-1977-score-reels-not-resetting/page/2#post-3683876 - see my curved red line --- a short wire runs from "one side of the coil to switch mounted on the relay - THIS is the Self-Hold-Switch - THIS is the switch You have wire-grey soldered-on - THIS is the switch in the JPG named "COIN RE."

IF (if, if) You can guarantee "THIS Self-Hold-Switch on the Coin-Relay is truely open (a stripe of paper sneaked-in between the contact points), have carefully examined short studs with the wires soldered-on: NO drop of solder fallen there - NO doghair-thin crap-wire fallen there - NO stud (blade) bent making faulty contact - can You guarantee this ?
IF (if, if) You can guarantee "Te Switch on the CREDIT-Relay (shown nearby in the JPG) is truely open (a stripe of paper sneaked-in between the contact points), have carefully examined short studs with the wires soldered-on: NO drop of solder fallen there - NO doghair-thin crap-wire fallen there - NO stud (blade) bent making faulty contact - can You guarantee this ?

IF (if, if) You can guarantee: The Jones-Plug (connecting Coin-door and mech-panel in the Cabinet) is truely unplugged - means "my green X really cut connections":
Unplug all "Coin Chute Adjustment plugs" - try the pin --- when now the Coin-Relay still pulls: I have no explanation.
Question: When You have the Coin-Relay faulty-pulling: Does the Credit-Relay also pull ?

Well, my often mentioned Switches*** are a possibility to feed the Coil on the Coin-Relay.
Another possibility is "all the wires I have 'marked with a green X' " - wires that have no connection when the Jones-Plug is unplugged. Greetings Rolf

Okay, if you determined that the coin relay switch is sending power to the score motor, then you'll want to look at the circuit that sends power to the coin relay coil. Also did you put a piece of tape between the coin relay switch that sends power to the score motor? This would determine if there is a short in the switch...

The gray wires lead from the coin relay coil and go to the 2nd coin chute adjustment plug and, depending how the coin chutes are set up on your machine, might go to the 1st coin chute adjustment plug, 2nd coin unit switch or directly to first coin chute switch via a different color wire. The gray wire also goes to the coin relay switch and the credit relay switch.

Here are the switches that send power to the coin relay coil:

1st coin chute switch - switch with yellow wire and white/blue wire (this wouldn't be a factor if the coin door was unplugged)
2nd coin chute switch - switch with yellow wire and yellow/black wire (this wouldn't be a factor if the coin door was unplugged)
Coin relay switch - switch with gray wire and blue/white wire
Credit relay switch - switch with gray wire and blue/white wire
2nd coin unit switch - switch with gray wire and white/blue wire (this switch may or may not be used in your machine)
Score motor switch 8D - switch with blue/white wire and yellow wire (this switch is normally closed)

You can do the same trick by using tape on the switches. You can also just unplug the plugs from the coin chute adjustment plugs.

Let's look at all the possible paths that power can get to the coin relay coil:

1st coin chute switch - not a factor; coin door plug has been disconnected
2nd coin chute switch - not a factor; coin door plug has been disconnected
Score motor switch 8D - switch is normally closed; power will pass through this switch
1st coin chute adjustment plug - not a factor; coin door plug has been disconnected
2nd coin chute connection (optional) - not a factor; coin door plug has been disconnected
Coin relay switch - switch will close when power is at the coin relay coil
Credit relay switch - normally open switch in the same circuit as score motor switch 8D
2 coin unit switch - not a factor; coin door plug has been disconnected
2nd coin chute adjustment - not a factor; coin door plug has been disconnected

So, if we look at all those factors, the only way power could be getting to the coin relay coil would be through the credit relay switch. Check the following:

Credit relay switch - switch with blue/white wire and gray wire

This switch is either not adjusted properly, there is a short in the switch stack / wire lugs, or there is power at the credit relay coil...

Rolf is a genius. Listen to his words. He will help you find the problem and he will help you fix it. A beautiful human. I speak from experience.

We'll need to confirm the source of the power to the coin relay coil. You can put a piece of tape between the score motor 8D switch - switch with the yellow wire and blue/white wire. Let us know what happens when score motor switch 8D is taped off...

After this, with the tape removed from the 8D switch, pull out the plugs for the 1st chute adjustment plug (white/blue wire) and the 2nd coin chute adjustment plug (yellow/black wire). I'm thinking there might be a short in one of these plugs that is allowing power to get to the coin relay coil...

Next, put tape between the coin relay switch - switch with blue/white wire and gray wire. See if this will cut power to the coin relay coil.

If no difference, remove the tape from the coin relay switch and then put tape between delay relay switch - switch with black wire and black/red wire.

Hi Herman
fredsmythson suggests "stripe of paper / tape sneaked-in in-between the Switchblades on 'Switch-on Coin-Relay (having soldered-on wire-blue-white, wire-grey)' ". I suggest : Do this and also sneak-in a stripe of paper into switch on Credit-Relay with wires of same color AND unplug the coin-door-wiring, then toggle-on ---

If still "no luck, the Coin-Relay immediately pulls-in and stays pulling" ---
how about "little gremlins at work - OK, OK - I (means You) do unsolder wire-color-grey away from "Coil on Coin-Relay" (((I would unsolder wire-grey --- of course You can unsolder away from other lug on the coil the TWO wires-color-black-red, YOU must guarantee that the TWO wires black-red still have connection to each other))). Tape the unsoldered end(s) of wires.
THEN You say "I am part of the logic of the pin -- I do what the Coin-Relay should do - I press the armature on the Coin-Relay - press - press - press - and let go "in time". And we proceed in looking what the pin is doing - it should reset the Score-Drums etc. - what is the pin doing when You do the work/logic of "Coil on Coin-Relay".

My snippet of schematics (post-10) shows Score-Motor-Switch-8-D involved - means: In a running "Little Joe" when the Coin-Relay is made pulling (and the pulling Coin-Relay makes the Score-Motor turn): AT EXACTLY the time the Switch-Stack on Score-Motor-Wheel-8 is actuated: The Coin-Relay is made "quit pulling" --- by now You are "part of the pin" - You manually press the armature on the Coin-Relay - press - press - press - and when Score-Motor-Wheel-8 actuates its switchstack: YOU let go on the armature on Coin-Relay - question: What does the pin do ? Nice resetting ?

I recommend - after a test: Toggle-off the pin - then toggle-on - then do a new test. (((To start a new game the pin likes to have the Game-Over-Relay to be in position "Game-Over" for to start a new game. And toggle-off / toggle-on should make the Game-Over-Relay move into state "Game-Over".))) Greetings Rolf

P.S.: http://www.pinwiki.com/wiki/index.php?title=EM_Repair#Bally_Score_Motor , http://www.pinwiki.com/wiki/images/d/d2/BallyScoreMotorFrontView.jpg (from left to right the cams wheels - 1,2,3,4 ... http://www.pinwiki.com/wiki/index.php?title=File:Bally_Motor_Switch_Levels.JPG the levels.
P.P.S.: Want to inspect the Score-Motor-Switch-8-D for proper "opening when actuated" ?

Hi Herman
great - progress. Does the pin reset --- I like to see the pin "reset" so I toggle-off the pin (Safety Reasons - Bally runs the steppers and activates the relays by 50 Volts AC - this can kill You - never touch bare wires).

I take out the 10 point score-drum of player-1, turn it around and let it hang on the wires - the pin can step the Score-Drum and I can manually put some points on the Score-Drum.
I then toggle-on - nothing happens - maybe the Game-Over-Relay is in state "as shown in post-36, this position is the 'latched position', the position 'ready to play' ". I then press the left flipper button and the lights turn on. IF (if, if) the Game-Over-Relay is in 'latched position': At the time of toggling the main power switch to "on": The pin moves the Game-Over-Relay into "OTHER position - moves into 'tripped position' moves into 'Game-Over position' " - question: In Your pin ?

I then start a new game (do the working procedure in Your pin) --- the Score-Motor starts to turn, the Game-Over-Relay is moved into "latched position" and the Score-Drums are stepped forward towards "position ZERO" --- the Outhole-Relay is made pulling and the Kicker near the flipper bats kicks the ball over to the shooter alley - and i CAN ACTATE the flipper bats - question: In Your pin ? Greetings Rolf

Hi Herman
we both live in Europe - it is daytime - I wanted to answer immediately so You can proceed in testing. Here text to Your post-36.

The whole goodie in the picture we call "Game-Over-Relay" --- a relay of "Interlock-Type" - it has a "Latch coil and Latch armature" - Your "B"-coil and armature ///// it has "Trip coil and Trip armature" - Your "A"-coil and armature.
A Nylon-Ladder is mounted on the Latch-Armature and switchblades are hooked-in into the ladder - the moving of the Latch-Coil moves the switchblades.

You write "when the pin is switched-on, relay A (Trip-Coil) is pulling immediately" --- questions: Does "when the pin is switched-on" means: When You toggle-on the main power-Switch --- or does it means: After toggling the main power switch - You press the left flipper button and NOW" ?
Does "relay A (Trip-Coil) is pulling immediately" means: relay A is activated, yes but obvious not pulling constantly, no constant humming of constantly pulling relay A --- or does it means: You hear a humming and You see: relay A is PULLING ? Good is when You have my first descriptions.

Post-36 "have unsoldered wire-grey" --- WHERE ? Away from the Coil on COIN-Relay ? Your "the other grey wire etc": I do not understand.
You have a good camera - please show a picture of "Coin-Relay" with coil and switchblades --- as You have it now - as You have it in the way "we can proceed in troubleshooting".
(((By now I simply do not understand how a coil can pull when ONE SIDE of the coil has NO Wire soldered-on on its solder-lug)))

The Lock-Relay must be non-pulling when the main power switch is toggled-off (of course there is no current - it can not pull).
The Lock-Relay should not pull when You (only) toggle-on the main power switch (it is not a catastrophe when it does pull-in and stay pulling - it is a minor fault to be fixed) - write about.
The Lock-Relay must pull-in when You press the left flipper button (or when You start a new game) and is MUST stay pulling until You (after hours of playing the pin, Lock-Relay pulling, pulling) --- when You toggle-off the main power switch: No more current available - no more pulling of the Lock-Relay. Greetings Rolf

Hi Herman
I had a confusion in my mind "Trip-Coil on Game-Over-Relay and Lock-Relay-Coil".
Truth is: When we toggle on the main power switch - a latched Game-Over-Relay will immediately Trip. The Lock-Relay does not pull-in when we just toggle-on the main power switch. The Lock-Relay pulls-in and stays pulling forever when we press the left flipper button or start a new game.

When I write "unsolder wire-color-grey away from 'coil on Coin-Relay' " I mean (see JPG, "orange C is the Coil, orange oval shows the place") unsoldering away from the coil.

You did unsolder away from the switchblade - the switchblade that has the short wire to one side of the coil. Lucky us (thats what I believe) - You have found the long-time-fault causing the Coin-Relay to pull-in when toggling-on the main power switch: The free, bare end I have marked with an "rosa, pink Question-Mark". I also believe You make a connection with Your Jumper-Wire: Along the connection Coin-Relay-Switch to Credit-Relay-Switch, my "orange star, question-mark".
I also believe to see wire-color-blue-white --- I marked it in the JPG: "blue dot".

I would tape the bare, free end "my rosa, pink question mark" --- I would have the Jumpering good, established (my orange star, question-mark). I would put the board back into the pin and reconnect the Jones Plugs (((of course: bare, free end "my rosa, pink question mark" is taped / has no connection))). Then I would toggle on the main power switch --- Game-Over-Relay is already tripped or it does trip when You toggle-on the main power switch. Have some points on a Score-Drum, start a new game by pressing the "armature of the Coin-Relay***" - what does the pin do ?

pressing the "armature of the Coin-Relay***" --- want to try to start a new game by pressing the "armature of the Credit-Relay" - what does the pin do ? (never forget to toggle-off and toggle-on the main power switch in-between tests) Greetings Rolf

0Little-Joe-Work-02 (resized).jpg

If you put tape on the delay relay switch and the coin relay coil was still energized, then there would be some type of short or wiring issue in the circuit.

If you look at the circuit with the coin relay coil, the electricity from the transformer starts moving through the circuit and it is "searching" for way to get back to the transformer to complete the circuit. So, here is a non-technical explanation for the pathway of the electricity in order to energize the coin relay coil.

- Electricity travels out of the transformer through a red/white wire, passes through a fuse and then continues on through a black wire.
- The black wire connects to a delay relay switch, the electricity goes through the delay relay switch and continues on a black/red wire.
- The black/red wire connects to the coin relay coil and the electricity spins around this coil and exits the coil on a gray wire.
- At this point there are three ways the electricity could travel, but you have disconnect the coin door from the main board.
- This leaves one remaining pathway to the coin relay switch and credit relay switch.
- Since the coin relay coil is not energized yet, the coin relay switch is blocked - the only way to continue is through the credit relay switch.
- The electricity travels through the credit relay switch via the gray wire and exits using a blue/white wire.
- The blue/wire connects to score motor switch 8D. electricity travels through the switch and exits using a yellow wire.
- The yellow wire connects back to the transformer, and the electricity arrives back at the transformer.
- The circuit is complete and the coin relay coil energizes.

So, just to confirm, if you put tape between the delay relay switch - switch with black wire and black/red wire - there would be no way for the electricity to get through the switch and it could never get back to the transformer using this circuit. Thus, the coin relay coil would not energize.

In turn, if you put tape between the score motor 8D switch - switch with blue/white wire and yellow wire - there would be no way for the electricity to make the final segment of the trip, because the switch is blocked and the electricity could not complete the circuit to the transformer. And, the coin relay coil would not energize.

This is why I'm thinking there is a short in the circuit or there has been some wiring modifications by a previous owner. Of course there is always a chance that the wiring on your machine could be a bit different from the factory, and it did not show these changes on the schematic... You might want to try putting tape in between the delay relay switch again to see what happens. This would be with the wires connected again to the coin relay coil. Also, unplug all of the following:

1st coin chute adjustment plug
2nd coin chute adjustment plug
3rd con chute adjustment plug(s)

As for the game over relay, one of its switches could send power to the score motor. But, the credit button switch would need to be closed and score motor switch 1E would need its second make/break switch closed. It's not likely that both of these switches have shorts or are mis-adjusted, but you can still check...

The delay relay should be labeled on the main board. The photo you posted of the relay with lamp socket should be the delay relay. You'll need to put a #455 bulb in that lamp socket to make the delay relay operate correctly. This might be what is causing the coin relay to be constantly energized. You can read more about the Bally delay relay at Clay's Pin Repair Web site:

http://www.pinrepair.com/em/index3.htm#oddities

You can still try to put tape between delay relay switch - switch with black wire and black/red wire - to see if that will block power to the coin relay coil...

You can also check the other end of the circuit by putting tape between the 8 D score motor switch - blue/white wire and yellow wire. If you unplug the coin door and tape the 8 D switch, this should block power from getting to the coin relay coil. But, if the coin relay coil is still being energized, then there is a short in the circuit.

According to the schematic that delay relay switch should be closed at the beginning of the game. Taping the switch at score motor 8 D should break the circuit for the coin relay coil. There seems to be a short in the circuit. Maybe a short in one of the switch stacks. You can always put everything back together and start looking at all the possible switches in the circuit again that might have a short...

Yes, you can do the tests on an isolated main board. If it's just the main board and you've unplugged the coin door, there would be only a few switches to look at. Take a close look at the credit relay switches and the 8 D switch. You can also do continuity tests on the switches with a multimeter by removing the wires from switches. This will determine if there is a short in one of the switch stacks.