To clean your Cisco IP Phone, use only a dry soft
cloth to gently wipe the phone and the phone screen. Do not apply liquids or
powders directly to the phone. As with all non-weatherproof electronics,
liquids and powders can damage the components and cause failures.
When the phone is in sleep mode, the screen is blank and
Select button is not lit. When the phone is in
this condition, you can clean the screen, as long as you know that the phone
will remain asleep until after you finish cleaning.