I removed all the wires, that did not help.
I give up, I think that the Shield just does not has the driver for this.
I'll wait for my G to be fixed.
Thanks for all your input.
You mean an alternative like going over to the the unit and turning the volume knob by hand like back in the olde days 
Oh, I have a working remote.
But the G display is tiny, I sit too far away from my screen to see it clearly.
The Arduino uses a large LED backpack:
that lights up every time I use the remote.
But to be in sync, it needs to communicate with the G.