Back onto Hot Tip tonight and was trying to figure out why the player 1 ball was draining and then jumping to player 4. Discovered the credit unit stepper switch was not missing any parts, but at zero position, the switch was below the bar/notch instead of above it. I discovered this issue on the pinrepair guide. I can now play a complete one player game of Hot Tip. Pretty cool!

My next aim: get the machine working in a 2,3 or 4 player game. From lots of observing and testing tonight, the credit unit is not progressing when the coil is fired. Looks like I'll have to remove the armature from the coil and give it a good clean like I did in the backbox for one of the stepper units.

Cheers!
Adam.