I got called to troubleshoot a 14 station system on a esp 16lx that customer says is 4 years old. Stations 10 and 11 no longer fire. Customer states they started to act funny by only going off for 5 minuted instead of the 30 they are programmed for, then stopped working all together. Tested solenoids. they work Valves open maunally. Pump start relay works fine. No problem with other valves. Took wires off of station 10and 11 put them on 15 and 16, still wont fire. Changed out solenoid (rain bird dvs) any way. No dice. Tomorrow Im going to bring a test clock to see if I get any different responses. ALL zones check out green with station master, I suspect bad common wire, but why would only 2 zones of the 4 on that common be bad? any if the wire was broken it wouldnt show up green I had this happen once before this year only (never seen it before that) where we common would carry enough signal for the station master, but not enough to activate the valve, when i ran a new common every thing worked. Even though station master said circuit checked out. On this property I cannot run a new common (500 plus feet of finished immaculate landscape) without causing humungous amounts to the client. If that is the case Ill probably run DC latching solenoids. Tomorrow Ill redo all the wire nuts just incase. But everything looked tight under quick inspection today. Anyone know of what else this could be?