The schematic is on IPDB but it's a poor scan - very out of focus. That said, it looks like the Double Bonus relay is driven by two paths. One is via a Make-Break switch on Score Motor 3B, if I am reading it right. The second path goes through Score Motor 4B through switches on the Outhole relay and Target relay. So it might be necessary to make sure the Target relay is pulling in when it should.
During game play, the Score Reel will be driven by the 10 point relay, so check that. If you close it manually, the reel should advance. If not, check switches on the relay.
