6 zone system. Zone 1 stopped working while the rest still are. I checked the wiring in the control box. It appears to be good. I replaced the solenoid for zone 1 and the valve opened. Now, zone 1 stays on continually whether the system is on or not. It continues running even if another zone starts. I can hear the solenoid working so I know it is getting power. I took the valve apart to look for dirt or rocks and didn't find anything. Please HELP as there is not enough beer to make me feel better about this situation!