Servos not responding to main out rails connections

I have connected my receiver to the pixmini via a ppm encoder. I have a power source going to the PM rail and also have another battery pack going into one of the main out rails. When i connect the servos. it responds by twitching once but seems the servos arent recieving signals from the ppm encoder to the main out. So how do i connect the ppm encoder to the autopilot and make sure there is signal being received by the main out rails please. i have connected the ppm encoder to the ADC 1/2 but is this wrong? Thank you.

Could you send a photo showing how you have connected eveything as that will help me to see whats going on. Also when your pixhawk is turned on, do you see any LED on the PPM encoder?

Finally got the servos working… Just needed to hold the switch button and turn it on. New problem is trying to get signal to the motor… The motor’s fail safe system keeps coming on. Only works well when connected straight to the receiver but we need the motor to run through the autopilot.
Thank you

Channel 3 is the throttle channel on the controller hence why it is connected in the reciever. Thanks again

Happy to hear you got your servo output working! From the looks of it your motors are not connected properly, you need to make sure the 3 wires are not touching - please see our ESC to motor connection guide