Three of our 4 zones are suddenly not working. We have a valve box that has 3 valves not 4 and two what look like white plastic test tubes with wires on the end. The valves look like the Rain Bird DV type. I could not turn the top of the valve to see if water comes out. Can I turn the bleeder screw instead? What are the things that look like test tubes? What else can I do?
