I’m sorry I meant when the station is activated via mobile application there is no change in voltage (24 v ac is not detected). I’m assuming there is no type of protection for a short when an expansion board is connected and I suspect that the shift register, processor or something fried even though there are no visible signs of component failure. This all started when I had a solenoid stick on and possibly short a station connected through the expansion board. The end result is now a mystery, more specifically why none of the stations are working. I think this is unfortunate because sprinklers solenoids are often exposed to moisture from flooded sprinkler boxes, busted sprinkler heads and leaking valves. If a short from a flooded sprinkler box or solenoid failure causes a complete component failure, I can’t see these boards lasting very long in a real time environment. These terminals need some type of protection from corrosion and shorts because its not a matter of if but a matter of when one of these situation presents itself. I am going to send the board back to see if Opensprinkler can figure out what happened.