have 4 sprinklers that will not cut off..have gone through all 15 stations to turn off and have unplugged power to valves and they still continue to run...finally turned main control valve off and they stopped but as soon as I turn it back on they start up again...everthing points to the valve controlling these 4 sprinklers...my problem is locating the valve...I know it's in the ground (have located other boxes on sides and back of house)... sprinklers are in the same general area (40 ft square ...
