System 10 yrs old. Rainbird RC-7Bi controller with 7 zones...using 6 of them. Turning of for first time this year. Strange...the odd zones (1,3,5) work fine, but the even zones (2,4,6) will not turn on. Controler seems to be running fine. If this was a single zone then I would suspect single valve, or valve wiring. But, all 3 even zones? Anyone know if there is anything that would affect half the zones?