Regarding Spark 3 cardio + music out of the box HR Sensor not working
I had bougth one 4 years ago, then 3 years ago I already bought a spare one. I tested it basicly but now it was time to switch and I see the HR sensor is not working. Yes I did a factory reset, update to the same version as my other device, activated the sensor. In tracking sleep and HR are of for the moment. Something I can do when I open it? I already replaced the battery once in my old one.
Any suggestion would be helpful.
Thanks in advance,