Hi Malcolm,
you wrote that the two satellite speakers work normally, but the Subwoofer doesn't. This means that the problem MUST be with the Subwoofer, because:
The satellite speakers are passive, so these two amps (which are built into the Subwoofer) work.
The stereo signal from the Genos to the Subwoofer (via the 8-pin mini DIN cable) is transmitted properly because the satellites are working. (The same signal is used to control the power amp for the Sub loudspeaker.)
I suspect that there is a problem with one of the following components:
- Sub pre amp
- Sub power amp
- Sub loudspeaker
- Defect of an internal cable or a circuit break on an internal circuit board somewhere between the 8-pin mini DIN Input socket and the named components.
If the Subwoofer still does not emit any sound, a Yamaha service technician will have to take a closer look at the device. But since it is, as you wrote, still brand new, I recommend that you simply send the device (the GNS-MS01) back to the seller and insist on an exchange for a faultless device.
Best regards,
Chris