Open the battery door and take out the battery to find the sticker on the inside – if white it has not been exposed to moisture, red it has been exposed to water.

If you need any further assistance with this question, please contact the Sonim Customer Experience Center at 1-833-MY-SONIM (1-833-697-6646) or email us at [email protected]  We are open 24 hours a day, Monday-Friday and we will further assist in troubleshooting.