FIXING JBL TUNE 220tws - Left earbud not working (how to)
Explains what to do when the left earbud of your JBL TUNE220tws wireless earbuds does not want to work even though it does power on.
In case the earbud does not turn on, make sure that the small pins in the charging cradle are not stuck in any way and that they can make contact with the earbuds.