With a new battery, it still wouldn't pair. I tried pushing in the reset button and noticed the LED flash red once. I then held the reset button in for 10 seconds and the LED still only flashed once. I then started googling for pairing problems, and followed a number of suggestions:
- Removed battery for 5 minutes
- put battery in backwards for 30 seconds
- un-paired sensor from 520
- un-paired HRM strap from 520 (only other device paired)
None of these attempts had any effect. The sensor just flashes once when you press the button...nothing more, and it's never detected by the 520. The wheel magnet is within 1mm of the sensor (almost brushing the arm).
Am I missing something obvious? Or is the sensor kaputt?