You may want to rent a wire locator. Although they can be tricky to use even for a seasoned professional. You might want to hire a guy. There's a possibility you have a broken wire somewhere. Testing the wires on valve 1 would help decide that.
www.sprinklerwarehouse.com/PRO-700-Rental-Wire-and-Valve-Locato-p/PRO-700-Rental.htm
Here's other ways of finding the valve. Poke around with a screwdriver in a logical spot. Follow the pipes with a shovel. Follow the wires with a shovel. Hook up a chatterer to the wires and listen for the valve. Of course that wont work if the wire is broken.
Good luck!