Wow - this is a great thread. My Core stopped transmitting data. Looks like I need to find an electronics repair shop and see if they can decode the people who are diagnosing the problem and likely repair.

Wahoo only says it will replace units now, not fix. My unit is old enough that not covered by warranty (and bought from a now defunct store). Incidentally, to be covered by a warranty one should provide picture of original receipt. Which I don't have.