well, that is conformation to me. Mine only does it in quick 1 second busts, but thats definitely it! I find it hard to believe that its not "servicable" as previously stated. Most solenoid valves are to a certain extent, if you know what you're looking at. True, the solenoid portion is just a coil, and once bad always bad. But the sound is probably chatter of the valve shuttle shifting repeatedly, or the squeal of the fluid being forced through a partially open orifice, or dead-heading because of the shuttle not fully seating. The fact that we all have some sort of an electronic force happening (the buzzing) makes me think its not a dead solenoid, only the inability of the valve to go where it should. I'm on vacation this week, but im gonna dig into mine when i get back