...there are no reactions to any buttons?
Reset the Polar heart rate monitor. Resetting clears watch settings which will return to the default settings. User information and measuring units settings will be saved.
1.Press the RESET button with a pen tip. Display becomes full of digits. If you don’t press any button after reset within one minute the wrist receiver goes to the Time of Day display.
2.Press any of the buttons once. The time of Day is displayed.
...the battery of the wrist receiver must be replaced?
We recommend having all service done by an authorized Polar Service Center. This is especially necessary to ensure the warranty remains valid and is not affected by incorrect repair procedures done by an unauthorized agent. Polar Service will test your wrist receiver for water resistance after battery replacement and make a full periodic check of the complete Polar heart rate monitor.
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