Question
I got new landscapers and they were fiddling with my irrigation system valves trying to turn my sprinklers on manually -  and after they left I found that my plants in station 3 weren't being watered, just a few little drops come out of the  lines when the station 3 is activated.  I have an in line valve installed under ground and I don't know the type, it has a solenoid with wires coming out of it on the left and a small black knob (sort of 4 point star shaped) on top of the valve itself on the right It looks something like a Rainbird 100CV.  I checked the rainbird site and it says the solenoid has an on-off capability, left is on, right is off for turning it on manually - and the black valve is anti-siphon and 1/2 turn counterclockwise will open the lines for manual operation.... It doesn't seem to have any capability for turning up flow. That is probably not what I have, because I really feel that the landscapers turned off my water flow... meaning that the valve has flow control.  I don't know the function of the knobs on the valve, do I dare turn it counter clockwise  to try to turn up the water pressure?  Or do I dare try turning the solenoid to the left (counter clockwise) and hope it does not fly off leaving a gusher behind?   

Or do I sound so hopeless that I should just call an irrigation specialist and pay him $125 for a service call to get it re-set.  I'd really like to find out how to do this so I can handle the situation if the landscapers start fiddling around with them again.... But is there any hope of figuring this out with an unknown valve?

Answer
Chances are the flow has been turned down.  The knob on top of the valve that looks like a big X is usually the flow control. Open it by turning it counterclockwise until it is fully open, then close it back halfway.  This is the proper adjustment for most valves.