I know what you mean about never looking at valve boxes - same with me. :). Remember, you don’t need to go to the boxes yet, you can/should check the valve wires starting at the controller without power. If you get some continuity across wires between Common and Zone 2 (60 Ohms or so) then your wiring should be good. If both the OHMS and VOLTS check out, I’d look for dirt in the solenoid area of the valve - the air “tubes/ports” (that create the vacuum to open) need to be free of dirt/sand. Look online on how to clean the valves.
