Cadence sensor dead after changing battery

I have the same problem. Changed the battery twice following the standard procedure and the cadence sensor remains dead.

What should I try next?

exactly the same. I used the sensor last time in early january. worked perfect.

put out the batteries from speed sensor and cadence and stored the bike and the sensors in a fresh box up to now.

Now, went back to training again with the bike and ..... cadence sensor do not work. Replace to full new fresh battery.... and another one...another one.... and another one. 

Changed this 4 batteries to the speed sensor is ok with the "old" battery and with the 4 new batteries.... so the batteries are ok.

CADENCE is dead? no leds. nor the "red and green" or the "green".... nothing... like dead. I usually be very carefull with my stuff and is the first time a sensor is failing.

Any clues?

thank you

Same problem here, completely dead, even with new battery. Any one with a help procedure, much appreciated.
Thanks!

well i have a new one straight out of the box, no green light on the sensor, no light at all. What am i doing wrong, never had a garmin device that didn't work out of the box

I went through 3 old GCS10s over the years (breaking the arm off myself a couple of times) and the newer motion based one before I gave up on Garmin cadence sensors and have gone with extra cheap (read: disposable) ANT ones online. The hub attached speed sensors is fine, but the quality or sealing or whatever on the cadence sensors has always been appaling.

I finally got the cadence sensor to connect.

When you open the battery, the connector on the battery lid needs to be seated just right so that when you close the lid, the connector hits the little bronze nub on the sensor within the battery compartment.

Hope that makes sense.

I'm having the exact same issue.  Did you return it?  

What just worked for me was prying the smaller connector upward a bit. Obviously it had gotten bent down. I was having no luck after changing battery and Garmin connect told me it must be dead...ha! The smaller metal piece inside the sensor was bent down too much apparently. Not sure how that happened, but pushing it back up a bit did the trick. Changing batteries on any Garmin device often requires something extra...so frustrating but thrilled to find a fix. Seemed unlikely that censor just died coincidentally with battery dying..and not the first time I've had this kind of problem.