Sonos Multi-Room Music System - Manual (Page 189)

Sonos Multi-Room Music System User Guide A-12
Long amber,
short white,
repeat ZonePlayer fault
shutdown (mute) If the fault condition
(above) is not remedied,
the ZonePlayer will
automatically mute itself to
prevent damage to the
ZonePlayer.
Solid or flashing
red Diagnostics mode You may be instructed to
enter Diagnostics mode by
a technician when you call
Customer Support to
report a problem.
If you accidentally enter
diagnostics mode, press
the Mute button to exit.