For a while my dad collected pinball and old arcade games as a hobby and actually fixed some of that up. We have quite a sizable collection in our basement now (around 15-25 pinball and some miscellaneous other cabs) a lot of them dismantled though. (Heads off the cabinets etc.)
The coolest machines in the collection however are our bowling machines, however none of them work. We've been trying to fix up the oldest one but we are having a lot of trouble with the scoring and frame display. The scoring mechanism is electromechanical and despite my dad being a former ET we are lost as to how to fix them. They get so far in scoring and then they just refuse to advance.
I've done some googling but haven't had any luck finding decent repair guides. Has anyone here had any experience repairing these and have any pointers?