There is a truly awful mech In these games related to the score motor - a plastic clutch that can break, and no replacement is available. At least last I checked.

Make sure it isn’t that first.

In the video, the second stack has bad switch arcing problem. Find out what the switch controls and troubleshoot that problem.

The Balll Return kicker solenoid requires that three switches close:
Joust Ball Return (resized).jpg
At the top the Match relay switch is normally closed. The other two, on the score motor and Ball Return relay close when the ball should be kicked to the shooter lane. To find the score motor switch see https://pinside.com/pinball/forum/topic/sky-kings-power-free-play-and-top-hole-issue#post-4457680

Any one of those switches could be dirty, or out of adjustment, or have a broken wire, etc.

/Mark

Hope these help , one will save on your back if you weren't already aware

Bally Joust Score Motor (resized).jpg

lift out bottom (resized).jpg

Please consider sending a good scan of the Score Motor chart to IPDB.org:
https://www.ipdb.org/machine.cgi?id=1317 -> "Submit Changes" in the upper right.

The bottom board needs to slide a little bit towards the coin door (step 4)

I always at-least finger-tight the 4 bolts when putting the board back I have moved a game before with the bottom board not secured ...

Sent a *.PDF ... seemed pretty simple, Thanks

Could someone elaborate on step #8

“Start relay trips clutch trip relay thru #5 cam switch which operates reset motor to reset all trip relays.”

Specifically, what is the reset motor? Is this separate than the score motor?

I’m having a similar issue with my Bally surfers, except that the play count meter steps up endlessly until I turn the machine off. I must have added over 500 games to the meter trying to troubleshoot.

Up till now I believed it’s a burnt step up coil on the ball count unit, which should fire once to step up to ball 1 after resetting score reels and all steppers. But seeing this thread leads me to believe it could be something else.

For a short time Bally used Motorized Trip Relays instead of conventional trip relays as shown here:
https://online.fliphtml5.com/vrtyz/pblg/#p=78
The Reset Motor turns a shaft with many cams that reset the trip relays individually. There are lots of discussions about them on the forum. The Score Motor is something else altogether.

How far does your machine get in this sequence of events.
With score motor service switch set to off.
Momentarily push the outhole switch.
Outhole relay should close and stay pulled in.
Manually turn score motor cams until cam 1 lifts it’s switch stack.
Ball return relay should pull in and stay pulled in.
Rotate cams until cam 3 drops it’s switch stack. Outhole relay should release and outhole solenoid should fire.
Turn cams until cam 8 drops it’s switch stack and ball return relay releases.

Yes that’s correct for some Bally machines uses a slip on connector for the service switch.

If the relays are releasing prematurely the 2 score motor normally closed switches to be checked are cam3 switch E and cam 8 switch D. Both are top of the stack switches making the top blade adjustment easier. Clean and adjust switches if needed. Check if relays now hold in and release at the proper time.

If it’s not the score motor switches then the relays hold switches need to be closely checked because the relays are opening way to early. Hold switches will have a wire going to the coil attached to it.

If the ball return relay isn’t staying closed check the series of normally closed switches on the 500, 3000, & 5000 point relays that also keep the ball return relay closed. The outhole kicker circuit was described above by MarkG.

hmmmmmm , "fires occasionally" suggests the coil itself is good. could there be a cold solder joint on coil lug or the common line from a previous location ?

Cold solder on a Jones plug?

On score motor, what's Cam 1F ?

"Completes pull in circuit for ball return relay" ... I didn't see "score motor 1F" on the snippet of the schematic above

then again you said you manually closed that relay with sporadic results

The ball return relay hold circuit consists of the 3 normally closed switches wired in series on those scoring relays, a normally open switch on the ball return relay ( hold switch), and score motor cam 8 switch D. Once the ball return relay is pulsed, one of those switches is letting the relay coil release almost immediately, instead of releasing it at cam 8.

It might be that the ball return relay isn’t getting any hold circuit voltage. Using a DMM set for AC voltage connect the black lead to the orange coil common wire and connect the red lead to the white-Brown wire on the ball return relay switch. A constant voltage should show until 8D is opened.

So aside from the new ball count issue, fixing that score motor switch fixed the kick out issue completely?

Initially right off the bat I found yesterday on the score motor switch stack 1, a cam follower was added to the bottom of the switch stack and installed inverted so that stack couldn't drop down properly into the cam notch. Removed that and adjusted stack 1 switches. Then found on cam 3, the cam follower was bent down in such a way that the end of it was also riding on the cam. This was causing the switch stack to keep the switches in a different state longer than they should have been because the end of the cam follower was also riding on the raised notches of the cam, drsfmd posted a picture of that in post 35. This was actually an issue on several other switch stacks. I found a few switches also not fully making on the score motor. After correcting those issues, along with cleaning the closed switches on the 500, 5000, and 3000, and match relays the ball return solenoid was working.
Drsfmd was able to play one game without incident. Go to play a second game and now it was stuck in reset, the reset relays were staying locked on and the replay unit would decrement all the replays on it over and over again. Eventually something would catch and it would finish reset, but then the player advance relay wasn't activating to advance ball to ball (This ended up being I overlooked the hiding trough switch that I wasn't manually activating while testing to try and get the player advance relay to pull, ding bat me). However it was consistently not finishing reset now.
So I took the game home and last night got it resolved. I went over the score motor again, found a few additional switches that were not making well/almost not at all. Also discovered that cam 2 was missing its cam follower, likely was the one found on stack 1. That was causing stack 2 to change the switch states later than intended. Replaced cam follower on cam 2. After I was done revisiting the score motor, cleaning and adjusting the switches, I put the game all back together and have no longer had the reset issue. Played dozens of games last night without any issues. This morning after several games it stopped scoring and was locking on the score relays. This one was easy and was just a dirty poorly adjusted switch on the 2nd player up relay. I will be playing more to see if any more gremlins arise but as of right now everything is working properly whether its a 1 or 2 player game.