I am an engineer.  Here are a  few debugging tips:

1) verify that you have water to the zone by using turning the zone on manually (there should be some youtube videos on this)

if this works:

2) verify that you have 24V AC from the transformer

3) connect the power from the 24v transformer directly to the wires at the wall for the  zone.  This should force the solenoid on.

if this does not work

4) have someone stand near the solenoid in the ground and repeat the above  (tapping the connection on and off slowly.  Do you hear a click.

if this does not work

5) get an extension cord and bring the wall transformer over the solenoid in the ground.  Cut the wire-nuts and connect the solenoid directly to the transformer.  (repeat 2 & 3)

6) how do you know there is a master solenoid that controls all zones?