@stromdiddily
did you check the belt instead of the sensor ?
https://forum.suunto.com/post/124621
if the belt is not waking up the sensor properly, then, probably the sensor looks dead.
just to be sure, do you have tested another new fresh battery ? i sometimes have new batteries somehow not powerful enough despite new
according to the video, try to plug the sensor on the belt and put both belt electrode in contact to each of them (like short circuit), if it definitively not make the sensor seeable, it is probably dead or something we may not think about