half my zones will not turn on
front lawn:
program A
zones 1, 2, 3
these work fine.
back yard:
prgram B
zones 4, 5, 6
these do not turn on at all.
i can manually turn the zones on, but they do not turn on with the control box.
i checked the wiring (traced it visually, no nicks or exposed wires) and it seems to be ok.
what next?