[solved] - Justboom Amp Zero - No sound


I just received my new Justboom Amp Zero, plugged it, booted up my Raspberry Pi Zero W, and setup as explained but my Volumio 2.389 remains silent

It seems everything is working flawlessly.

My hat is recognized :
Volumio - Audiophile Music Player 2018-06-08 18-34-03.png

even at a lowest level :
3. volumio@boombox ~ zsh 2018-06-08 18-36-21.png

the playback looks all right :
Screenshot_2018-06-08 deadmau5 - 4 - Fn Pig.jpg

but I can’t hear any sound from my testing setup :

I previously used, with this RPI 0, a teradac ES9023 with an external amplifier that I’d like to replace with and smaller and more compact solution, but I can’t make it work.

What did I miss ?

Ok, it seems the JustBoom GPIO female pin are responsible of this issue…
While plugged, moving the hat from one side to another made the sound appear (and disappear again)…


Anyway, sorry for the noise