Pixhawk 2.1 Cube no USB connection

I’ve got a new Pixhawk 2.1 Cube and connecting it to a computer (Ubuntu 16.04) via USB doesn’t work.

QGroundcontrol doesn’t register the connection at all, and using lsusb the device has no name, but is assigned a bus and id.

The pixhawk itself just displays a constant orange light during this, after a brief flashing orange light upon plugging in.

I have tried powering it via a LiPo and connecting via USB bu the result is the same.

I have tried removing the SD card, and using different cables but neither worked.

I have seen that re-flashing firmware on sd card manually may be an option.

Thanks for any help

The cube was confirmed to be faulty- so we have a replacement on the way.