Just bought a new SUB but I think it has a hardware fault. At no point does a light come on. It's got power because the system detects a new SUB, displays its MAC address, and attempts to connect. Setting up by wireless and wired connections both time out. Factory reset does nothing, including no light. Unplugging other SONOS devices one by one in case of some duplicate IP address issue with the router doesn't change it.
Is there anything else I can try before declaring it a hardware defect and pursuing an exchange?