FrSky OpenTX and S8R Self-Check Activation Fix No Servo Outputs 

Sometimes the S8R (or other stabilized system) may not output the stick commands to the servos.
In this case it is usually that the self-check procedure must be run.
This is the basic demonstration for activating self-check on OpenTX with the S8R receiver.
For other stabilized systems like ARCHER SR8-Pro / ARCHER Plus SR8 or RB-xS systems, please refer to the manual for the self-check activation which is performed via the Device Config -- SxR or other required Lua Script.