Turn on one of your zone valves manually, do you have water? If not, check the water meter -(if other than the one for your house), or see if you have an isolation gate valve that shuts only the sprinlkler system thats been closed. If you have water, then check to see if you have power A) to the clock, and B) from the clock. Checking to the clock, has a breaker been shut off or possibly tripped, if so reset it. If the clocks LED Display is active then you should have power. More often than not, the LED will display - NO POWER - If there's a battery back up that's still active, disconnect to see if LED's powered by it. To check A) power from the clock and B) Wiring to the valves, all you need is a working solenoid. Remove the white common wire(s), or whatever color wires are connected to the clocks common terminal , then take one of the solenoid wires and wire nut it to these common wire(s) you removed from the terminal, take the other solenoid wire and connect it to the common post in the clock. Now turn on each zone via the clock. The solenoid should actuate if there's - A)power from the clock, AND B) if the wires are good traveling to the valves. If their all dead, (solenoid does not engage for any of the zones), then at the very least the common wire has been cut, the solenoids are all bad or multiple wires have been cut. If the solenoid clicks on some of the zones, then only some have solenoid or wiring problems. Remember, normally, the common travels to all the valves while the lead, or hot wire only travels to individual valves. Check anywhere in the yard you've dug for plants, fencing, yard decorations or anything else underground, you'll probably find the problem. If you've had lightening strikes or power surges, you may find you have solenoid problems, these can also affect the clock as well. If you find the cut wire(s), take care to reconnect them according to their color code, or correctly, especially the COMMON wire(s). After testing, reconnect wires back to the clock as they were originally. ....