Question
My sprinkler system worked fine for 6 years and this summer I noticed the ground cracking really bad in two parts of the yard. Well, I did a little investigation and now found out the entire sprinkler system will not come on. I tried to test each zone individually from the controller and then I tested each zone individually at the valve to each zone. I have not ohm each zone at the controller yet but will do so. Rain Bird's website recommends I check each each terminal for 22 to 28 volts. Once, I do that if the voltage checks out, What is my next step? Replace the controller?

Answer
Sorry for my late reply.
You didn't say if you could get the system to run manually. (at the valves) I'm assuming you can manually turn the valves on.
If you test the terminals of the controller and your getting 22-28 volts the controller is fine. It's sending out the signal to the valves.
Next step would be to look for a cut wire. An other possibility would be the common wire is disconnected. Check at the first "closest" valve to the controller for this. If the common wire is a problem here it wouldn't allow the rest of the valves to run.
Let me know how your ohm test workout. It will give me additional info I need to help you.

Matt