At part of build when connecting servo to main board of Rover and just get hummus, no movement. Tried another servo that i use on RC airplane and it moves fine !!! All 3 of my servos won’t move on Rover main board… I have brand new duracell batteries, and Have tested voltage of each battery pack = 4.68 volts. FYI, I have placed a Rover servo on my airplane receiver and it works fine there!!! Seems like low voltage on Rover to servo …Please advise… Randy