Sonos Sub Gen 3.

Hi @RonCranham, Thank you for reaching out and welcome to the community. Sorry to hear about this issue on your Sonos Sub, and thanks for sending a diagnostic report to check your Sonos system's status. Upon checking, It shows that the Sonos Sub is offline. And it may have dropped off your system. Since you’ve done a reboot on the Sub, kindly reboot all the other speakers you have and the Sonos boost. Unplug it for 1-2 minutes and replug it back in. and let’s see if the Sonos Sub will be back online. Also, does it show the Sonos Sub on the list of your Room? or does it show a “+?” on it?

Let me know your thoughts with the advice above.

The Sonos community is always here to help.

Hi @RonCranham, thanks for the quick update. If it shows +? on the Sonos Sub, Kindly perform these troubleshooting steps on Removing and reading the Sonos Sub, and let’s see if it would work.

Removing the Sonos Sub.

1. Tap the
   Settings tab.
2. Tap System and choose the HT Room Name appearing as Room (+LS+RS) or ?
3. Select Remove Sub.
4. Select Next to remove the Sub from your home theater setup. and Readd the Sub
5. If you want to associate the Sub with a different Sonos product, select Choose Room for Sub and then select another room or the Room where your Home theater setup is.

Let me know your thoughts with the advice above.

The Sonos community is always here to help.

The ? implies it’s not properly registering with your router, and receiving all the necessary information. So I’d be looking at two things. Neither of which make a lot of sense to me, but there you go, and some extra troubleshooting might help.
 

First, double check to make sure the WiFi (radio) is turned on for the Beam. Precautionary, but the Sub connects to the router through the Beam, and not directly. I don’t think this will be the issue, if your surrounds are working, but it is worth double checking. 

Second, try a network refresh, to make sure that the router has some free IP addresses to give to it through the Beam. Unplug all Sonos devices from power, then while they are unplugged, check for software updates on your router and apply them, and finally reboot the router. Once the router comes back up, plug back in your Sonos devices. Check to see if that ? has gone away, and way the extra 10 minutes or so to get past that 5 minutes you were talking about, and test.

I’m really doubting it’s a failed device, though, since it is actually reporting a ? to the system, rather than being completely missing. But that is a guess, the diagnostic should be a good indicator for Simon to investigate, but it actually probably requires the device to show up.

One final thing to try is to connect the sub to the router directly, although that’s not the normal way that the Sub connects to the Beam. If the Sub is having an issue getting an IP address, connecting it directly won’t help that. The reboot of the router might. 

Did the replacement sub work?