Quoted from "pphilt" I guess I could just get 75 ft of 14 g single strand and bury it and say to heck with it? thanks, PHil That is exactly what you should do.
Run your system manually by way of the valves. Locate your valves inside your valve box. Turn one valve on at a time until you figure out which one controls the zone that is drizzling. I'd go ahead and just have them replace the entire valve. In my experience, it's never as easy as just fixing the diaphragm. It's probably time for a brand new one anyway.