I have SERVOn_MIN SERVOn_MAX set to 1100 and 1900, it works fine when ardupilot is running.
The problem is the power-up moment. When I plug-in the battery, the servo immediatly turns to one very end, probably the position of 800 PWM value, and it breaks my rudder. At the moment, OSD shows “initializing ardupilot”. After initialization finished, the servo goes to the correct position again.
Looks like the controller is not giving a right PWM value on initialization, what parameter controls the power-up servo value?