SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

About a 10 year old pop-up sprinkler installation in a lawn, 2 valves each control 1/2 of the lawn, been working fine forever. All of a sudden, one side of the lawns sprinklers ALL barely have pressure? I flushed all the sprinklers by unscrewing the ends and running water through them but the water flow even with the heads off seemed low? Is there a way I could pull apart the control valve inside the manifold box to see if something is jamming it up in there or?

There are three valves in the control box running off the same water line on a 3 way manifold, never have had a problem since installation. Don't see any obvious leakage or wet spots between valves and lawn . . . any ideas?