Garmin HRM-Dual not working

So I'm having same problem for a year now, bought HRM dual in, Dec 2021, it connects fine and shows 72 or 74bpm on edge 1040 and then no info, two dashes, zero heart rate... I ended up buying a polar that works like a charm. 

I did all the battery reverse bullsh*t and didn't work.

Just out of curiosity I plugged the Polar sensor to the Garmin strap and guess what? Worked perfectly! The strap is definitely not the problem, the HRM Dual is acting up, so what now garmin?

This worked for me (a relief so I don’t have to buy a new strap). April 2024

My dual alsof stopped working after 1 month, I mean this should 't ben legally possible for a €40 HRM sensor bet yet here we are, thank you Garmin tot make the more expensive things the worst things

This happened with the battery installed upon purchase, or you changed it and it only worked for a month - please explain.

On purchase, i thought the thing would last me a while bit apparently not

7679997 said:

On purchase

Then I wouldn’t worry, the battery could simply be old and this is self-discharge of the battery, and not a problem with the sensor. Just change the battery and see what happens.

I thought the battery would last 3.5years or am i wrong?

The battery life depends on the capacity (quality) of the battery itself and the intensity of its use.

You cannot say that a battery will last 3.5 years without specifying that it is a fresh battery and how it will be used - an hour a day, two hours a day...

That worked for me!