POLAR S610i - Manual (Page 82)

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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. The guarantee does not cover damage or consequential damage
caused by service not authorised by Polar Electro. 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.
...the data transfer from receiver to computer was unsuccessful?
1. Check the correct position of the wristwatch receiver with the infrared
window of the computer or the optional interface.
2. Check that the surroundings are not too bright. This problem often
occurs near windows.
3. Check that there is no obstruction between the infrared windows.