If the Squeezebox Duet gets disconnected from it's LAN cable it will move to Wifi... and will not move back automatically! To restore to wired operation the player needs to be reset. Here's how to do that.
Method 1 - partial reset
- Push control botton on Duet receiver and hold it down until it flashes red
- Shut off the Duet controller
- Turn on Duet controller
- If required, select a netwerk
- Select another receiver (if you have one, see note below)
- Re-select the Duet
- The controller should now give the option of ethernet
- Wait a minute or so
Some people report that if they had better results if they at step 5 first selected another player (even a software payer such as SqueezePlay) before reselecting the Duet.
If the above doesn't work (it did not always work in my case) try method 2, which is rather painful as you have to enter network and password...
Method 2 - full reset
- Restore Duet Controller to factory settings
- Push the button on the Duet Player until it flashes fast
- On the Duet Controller choose langauge
- Connect to other networks
- Pick your wifi network and enter password
- All other networks
- Choose player
- Wait a minute or two