Are the scoring reels all resetting to zero? If so, that's a good sign. If not, manually set them all to zero (with power off) and try again. The scoring motor running on and on is very common when an EMs been sitting a while.
If there's no on/off switch in the normal spot,
some older EMs turn on and off by hitting the bottom of the cabinet. I think that stopped before Top Score though?
BTW, great thread title Ricky Bobby.