We tested the sprinklers a few months ago and they all worked. Now only those in one zone work. All others don't respond at all, as if wires were cut. The control panel is in garage. On the outside wall I see the pipe containing the wires go to the ground. A few feet to the left there's a capped well (what do you call it?) about 4'' wide. This is the side of the zone that works. I looked inside the well and saw some wires and two cylinders. To the right of the wire pipe there's no such well. But around a far corner of the house I see two similar wells. They both have 2 white wires, 1 red wire and one or two cylinders in them. I suppose these are for the sprinklers and at least one cylinder is a solenoid. But none look in bad shape and the cylinders can't be (easily) taken out. Previous owner had a good drawing of sprinkler heads. But the current problem is I don't hear anything when the control panel dial is switched to any of these zones. How do I go about troubleshooting? If needed, I can show pictures. Thanks.
Yong Huang