I have all 4 rx wire connected to the board, volume control, power, speaker.
-tx power on (Spektrum DX7S)
-Ibu2 power on (green light blinking slowly on the board), short elevation sound.
-the RX bind light is on (Spektrum Ar400), rx has been checked with servos and work properly.
Put the dip switch 8 to ON, move sticks in all directions, then pull back the switch 8 to off.... nothing .

I tried 50 times, with different batteries, with an other radio (Futaba T7j, R2106GF Fhss).
At One time, I've had the elevation, MG, gun sound on chanel 2 working, but then I tried to recalibrate and I lost it...

Here is a picture:
