I hope I understand this correctly. The switch gaps on the score reels are critical. In the '9' position, the mid and top switches should be open. If the top switch is closed, the score reel won't advance.
As for a ground causing a short on the score motor, I've had that happen after reassembling the 'C' switch stacks. Another thing to check are ALL of the switch tabs. Make sure there not touching other tabs unless it looks factory. Hope this helps