Upon occasion, we have had one or more Sonos zones simply disappear. Usually this happens after some network changes or interruption with power, but the zone simply does not want to show up. Well, here are some tips to try to bring it back to life.
If Sonos is having trouble 'seeing' one of the units, try unplugging the power to the offending unit for a few minutes, plug it back in and try "adding a zone".
If this doesn't work, unplug ALL of the Sonos units in the same way. When plugging them back in, start with the unit that is connected to your network (if you have more than one that is wired, plug these in first). Then plug in each of the units.
If you are still having trouble, repeat the above, but while the units are unplugged reset the controller.
If you have the older CR100 controller (the wide one with the iPod-style touch wheel), press and hold the upper left and upper right hand buttons (the music and mute buttons). The controller will beep and the screen will flash to indicate that the controller is resetting. Proceed plugging in the units as described above.
If you have the new touch-screen controller (CR200), go to your music menu, then to settings, controller settings, advanced settings, restart controller. Proceed plugging the units in as described above.
If you are still having problems, or are moving the system to another location (another house, not another room), it is a good idea to do a factory reset of the controller.
NOTE: All of the references to your music library will be cleared. You will have to reconfigure your music.
If you have the older controller - the wide one with the touch wheel (CR100), press the music button,
If you have the new touch screen controller (CR200), go to your music menu, then to settings, controller settings, advanced settings, factory reset.