Could be the cap tilted and let the rotor snap off the little contact that makes the bridge between the coil wire and the spark plug wires..
I've seen many distributors up here with busted off cap hold down screws--usually someone puts a zip tie on them to help hold the cap on,when they were too lazy or cheap to drill it out and fix it right,or get another distributor..
I've seen many distributors up here with busted off cap hold down screws--usually someone puts a zip tie on them to help hold the cap on,when they were too lazy or cheap to drill it out and fix it right,or get another distributor..