Hi Pinside Friends. I would enjoy your thoughts or direction. Just picked up a #Big Shot yesterday and found the score motor running continuously as well as a Roto type unit that could be keeping track of ball count or what ever, see photo (I have ordered a schematic from Marco). Also the " Tilt Hold Relay " pulses with the Roto unit while still being energized and then every cycle it de-energies for one score motor pulse. Your thoughts or direction would certainty be appreciated.

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Thanks for your help Mark. To your point Dr, "C" the "Add Bonus Unit Relay" is energized. Where to next guys?

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Sorry to say there was a little more going on than I realized. What I missed was that HB, ZB, QB1, QB2 were latched. After resetting them I powered back up and they again energized.

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It has a tag on it that says Runout Switch and when the cam allows the contact is open.

So to summarize:
Coils Energized or Latched
C (Add Bonus Unit Relay)
HB (3000 Bonus Value Relay)
ZB (1st Player Relay)
QB1 (Game Over Relay)
QB2 (Game Over Switches)
and a rotating Runout Switch/(Bonus Unit?) unit that actuates over and over along with the
Score Motor that runs continuously.

Any ideas on what these might have in common?

Ok, while looking this over today and resetting the RESET BANK (HB (3000 Bonus Value Relay), ZB (1st Player Relay), QB1 (Game Over Relay), QB2 (Game Over Switches) it actually stayed clear. It now stays just like that but now its doing something completely different.

Three things remain the same as before
1. Coil C (Add Bonus Unit Relay)
2. Rotating Stepper (Bonus Unit?) Solenoid w/attached Runout Switch that steps over and over.
3. Score Motor that runs continuously

Coil O (Ball Return Relay)
Coil Q (Ball Return Control Relay)
Coil A (Alternating Relay)

The targets reset and ball return runs over and over with the Rotating Stepper (Bonus Unit?)

I can't wait for this wiring diagram to arrive! In the meantime your help is greatly appreciated. - Tom

Well I didn't see this the first time through. There was damage to one of the contacts on C, a NO contact that was permanently closed. 20190825_143709 (resized).jpg20190825_143740 (resized).jpg After straitening that out the game is silent.

As I coin up I hear the Credit Unit Assembly actuate and but no credits show on the wheel. While manually actuating the numbers they never quite make it to the front viewer so its blank. Regardless when pushing the replay button nothing happens. I will begin to look as for why the "S" relay doesn't engage.

As far as the hand written part of the diagram if the contact that interacts directly with the ball rollover is NO with no ball than it has not been updated right?. 20190825_124823 (resized).jpg If the ball enters the ball return it then closes. So is my interpretation correct here, not upgraded? - Thanks again for your help! - Tom

A great explanation of Credit Unit operation. Mine is jacked. The contacts where apparently not limiting the set direction limits and the spring is wrapped around more than it should be and the contacts are all bent up as well. Getting the contacts back where they belong will be a challenge to figure out. Mostly for the same reason most things on this machine are, wire identification. You would swear the wires where out in the sun for 30 years catching a tan in a humid climate based on the amount of corrosion is on everything else electrical. My toughest EM to date though its only my third.

So was my interpretation correct here, not upgraded to the handwritten portion of the posted schematic?

Gotcha. Seems it wasn't updated to the hand written revised schematic. I have been a bit distracted with a fence project in the yard which I just finished yesterday (about 350 feet worth).

Present Status: Can't coin up. Three relays close in the Control Bank as I turn the power on, two have coils. Its ZB,(1st Ball Relay) QB1 (game over relay) and then consequently QB2 (game over switches) is pulled in with QB1. It seems this game has a number of issues.

Good call! I need to do further examination however I held in "V" contact in and pressed the credit button and it worked. I powered it off and just pressed the credit button and it works now and kicks the ball out. It must have been some corrosion.

That said the score reels are not recording a score (no chimes either) even though I can hear the score motor running. After hitting the credit button I can hear a reset taking place but the numbers are already zeroed out. Also it does not recognize the ball when it drains to advance the ball in play.

@howardr @markg

So here is the latest snag on this. If I score anything that involves "1st Hundreds", "ZB" locks in and consequently the "Ball Return" will no longer function. So is the a normal operation of the circuit and the circuit path is then ment to pass through the bonus unit?
FYI: The mysterious hand writen part on the diagram (involving Coil "Q") is not pysically part of this game (If it did would it resolve this?).

Thanks for your continued support on this troubled game. - Tom

Sorry, I didnt mean to imply the coil is energised, it isnt, just locked.

I was looking hard at Solenoid "Q" due to the "Ball Return Sw" in that circuit. So when I saw "ZB" being energised I thought there might be a problem with that or with the "Bonus Unit" completing the circuit. Still getting my legs on circuit logic.

I will begine to check out contacts on "O", Motor Contactor #4, Level C and "XB".

Contacts and connectivity are just as stated in the drawing. Proper voltage was also being applied through XB to the associated side of Motor 4C contact which was open as well as O.

After coining up and closing the NO Ball Return Switch, Q (Ball Return Control Relay) energizes and consequently the Ball Return solenoid fires as it should. However after scoring 100 points or a multiple thereof ie 500 Points ZB contactor energizes and then latches. This then opens a pathway to Q preventing the Ball Return solenoid firing.

There is another path that should be working though and its through the Bonus Unit.

I checked the Bonus Unit mechanically at first. It was sluggish and not snappy at all when actuated. I replaced two springs. This is when I noticed two wires had become entangled with the Bonus Unit Auxiliary Contacts. They were holding the contacts apart. This may have been a self inflicted wound when I had the play-field out leaning against the pin, I'm not sure but this machine was a real rescue and challenge seeing it had of 24 separate issues preventing it from operating. It had seen abuse, heavy corrosion, damaged components and foolish attempts in its past to repair it. Its a real joy to have it working completely now. Thank you all!

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Yes, it is. However, as I have played about 10 games on it, it will at the start of a ball or mid game stop scoring and ringing the chimes. The 8 Ball hole kicker will not function when this occurs also. When the ball drains it will score and chime any bonus collected. This is intermittent. Often times the next ball works fine.

It might be a strange approach but the 8 Ball kicker circuit seems easy to me so I will wade in at that point and see what I find.

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It didn't take long for it to happen and I got it to repeat a short time later and both times I found this. The Score Motor is cut short on it's full rotation cycle. So, contact “Motor 1C” must need the gap adjusted. I'll give that a go and see what happens.

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