Valve repair is the call when one station does nothing, or when a zone keeps running after the clock has moved on. In Lewisville the box is often the slow part. St. Augustine and mulch bury green lids. Clay heave lifts them until the mower clips the corner.
Open or closed
A valve stuck open floods one zone and can keep the meter moving overnight. A valve that will not open leaves that station dry while the others look fine. The box is opened. The solenoid, the diaphragm, and the bleed are checked. Grit from a main-line break upstream is a common reason a Lewisville valve fails in July after the same solenoid was already replaced once.
If the solenoid is good and the station still will not call, the wire is checked at the valve and at the controller. A nicked common in an older manifold is not a reason to condemn the clock. The clock is replaced when the clock has failed, not because one station is dead.
After the valve is done
The lid goes back to grade so it can be found next time. A cracked manifold is a different repair from a solenoid, and it is priced before the pipes come apart.
If a zone will not shut off tonight, call (940) 239-0007. Close the water at the backflow if water is leaving the yard, and say that you did.