Disabled channels

ArduCopter Copter 4.4
1

I have connected a traditional RC servo (for 1-axis camera gimbal control) to the M3 pad on my Kakute F7 AIO — I understand that this pad corresponds to the Servo2 position. When I assign this servo the function 7 (Mount1 pitch) I get no output to that servo.

https://ardupilot.org/copter/docs/common-holybro-kakutef7aio.html

RC7 is properly calibrated as per the “radio calibration” page and shows that the FC is getting the desired signal on channel 7
RC7 function is set to 213 (Mount 1 pitch)
Servo2 function is set to 7 (Mount 1 pitch)

Similarly, setting Servo2 functin to RCIN7 also does not result in any output.

What am I missing here?

2

Check BRD_SAFETY_MASK , it’s a bitmask so you need the bit set to match the channel you want to allow activity on before arming. Reboot required to take effect.
The doco says the outputs are enabled or disabled by the safety switch, but I suspected it really refers to being armed or disarmed, since many people no longer use the safety switch.