Orbit sprinklers rely on a series of control mechanism to work properly. A valve, solenoid and timers all work together to keep the water flowing. If any of these devices is damaged, the sprinkler may not shut off automatically.
Every sprinkler system relies on valves to control the flow of water to individual zones. A broken valve can mean water will not shut off automatically. When this happens, try turning the tab or ring on the black solenoid on top of the valve clockwise until the water shuts off. This ring or tab sits around the base of each solenoid. You can also shut off the water manually by turning either of the two ball valves that are located on the pressure vacuum breaker device just above the sprinkler valves.
Solenoids sit on top of valves and control a small plunger that turns water on and off. If you are using a manual sprinkler system, these solenoids are the control point for each valve. If the water won't shut off when you turn the tab or ring at the base of the solenoid, you can try twisting the entire solenoid clockwise. The added pressure will usually shut off the water.
Timers are the heart of automatic sprinkler systems. A timer sends an electric signal to the valves to turn them on or off. A broken timer will not send the signal for a sprinkler to begin or end its cycle.