Question
When I turn on my sprinkler system, all zones come on at the same time,
instead of individually. What could be the problem?

Answer
If its doing this when you open the main water valve, then I would suspect that the irrigation control valves have been manually opened, and the manual bleed device needs to be shut off.  If the probelm occurs when you try to operate the irrigation controller, then it is most likely a controller problem.  Try resetting the controller by removing all the power connected to it including any battery power, wait 3-5 minutes, then reconnect the power.  If this doesnt help, check all the wiring connections at the controller and at the valves to make sure there is not a short.  But I suspect it is an issue with the contrller.  You may have to replace it.