Panasonic KX-TG7875S Operating Instructions Manual page 76

Useful Information
Liquid damage
Problem
Liquid or other form of moisture
has entered the handset/base
unit.
Caution:
R To avoid permanent damage, do not use a microwave oven to speed up the drying process.
76
Cause/solution
R Disconnect the AC adaptor and telephone line cord from
the base unit. Remove the batteries from the handset and
leave to dry for at least 3 days. After the handset/base
unit are completely dry, reconnect the AC adaptor and
telephone line cord. Insert the batteries and charge fully
before use. If the unit does not work properly, contact an
authorized service center.
For assistance, please visit http://www.panasonic.com/help