Nothing like an easy answer eh?
Do you know where the valve that operates zone 1 is in your yard? That would be the first place to start....if you know where that valve is located...go listen to it when it is supposed to be running...9 times out of 10 times that valve will have a bad diapragm...you can tell this because it sounds like it is trying to come on...hissing sound.
If you know where the valve is and it is making this sound....gut the valve, meaning replace the diapragm, and top, and solenoid all at the same time...make sure pump isn't running when you take the valve apart...!!
If it isn't hissing than there are more things that you can check...however, we will need to know what your experience with an OHM meter is before we can help you with that...
Good Luck
Sprinkler Solutions, Inc.
Arizona and Colorado
www.sprinklersolutions.net