I looked at the schematic and I'm surprised it doesn't have a separate listing of the score motor stacks and where they go. I know on my Williams games there is a switch on the score motor that the credit button gets its connection from. If it's out of adjustment the game won't start even set to freeplay. If you had some mangled switches, that seems suspect. A visual examination can usually see how they should be adjusted. Hope you get it fixed, I enjoy that game and yours is in fine condition.