Very cool game, on our want list
Sounds like there could be a couple of things going on, the usual EM stuff like dirty switches, misadjusted relays, or gummed up steppers. If sky jump has a manual, you could walk through the startup sequence go see how far it gets before you get the motor cycling.

The reason the motor cycles is because it has gotten to a certain step, but the step hasn’t completed, so it keeps trying over and over. The trick is to figure out exactly where. Are the score reels reset? Is the ball count reset? Is the relay bank reset? That kind of stuff.

I did notice the “A” relay in your pictures. Our king pin and pro pool have that relay. It’s a latching relay the gets kicked off by one coil when you start a game and then reset by another coil when it’s done. The latch works by arranging the relay actuators so that they click and hold each other until the reset pulse. I have run into the case where they get dirty or out of adjustment and then the game does exactly what you’re describing.

This guide helped me out a lot with this. There are associated videos on YouTube that help.
http://www.pinrepair.com/em/index3.

I wish I could be more specific, but I don’t have the docs for that game. One thing that I do is to search for the game on pinside and then select the forum tab to get all the postings that link to it. You can often find someone who has run into exactly the same problem.

Good luck,
Dave

Exactly, I’d walk through step 3 and 4 to see how far things get.
If it all looks good, watch carefully for the A-reset coil trying to pull to unlatch A.
I was able to feel the hum of the coil and that’s what led me to finding that I needed to clean up the latch plates. It doesn’t take much crud to make them stick. The score motor contacts energize that coil for a very short time.

Dave