Question
I have rain bird 600 system.  When in manual mode, valve station #1 works normally, when set to station 2 #1 valve opens but not #2.  Any ideas as to why?

Answer
Hi Tom

Check the valve solenoids, move the #1 to # 2 and see, if the problem persists, valve 1 always open, probably you have some foreign object inside the valve, open it and clean. If 2 not open, most probable cause is a bad solenoid.  

Regards
Guillermo