JBL Vibe 300TWS

As with all in-ear headphones, our range of TWS headphones can be susceptible to a build up of dust and earwax. This can cause low volume on one or both earbuds, or balance issues (e.g. right earbud is louder than the left earbud). To reduce the likelihood of these issues occurring, it is a good idea to periodically clean your earbuds and your ears. Clean the earbuds by removing dust and wax after each use, using a pointed toothpick to remove larger amounts and a small amount of rubbing alcohol applied to a cotton swab for final degreasing.

If you are experiencing volume or balance issues, always check for wax and dirt in and around the earbud and driver and complete cleaning of the earbuds as described above. If the issue persists, there may be earwax/dirt stuck in the small holes in the grille in front of the driver, preventing sound output. To resolve the issue try dipping the affected earbud tip into a solution of lukewarm tap water and a small amount of dish soap (washing up liquid). The earbud tip should only be put into the liquid up to a maximum depth of 1-2 mm only (see images below). Immersing the earbuds in water or putting the earbuds in water at a larger depth than this could void your warranty. Keep the earbud tip in the water for about 2-3 minutes, then wipe/clean the grille with a small brush (such as a toothbrush). The should remove the wax and resolve the volume/balance issues.

 

Double-tap the button on the right earbud, then on the third tap - press and hold the button for more than 5 seconds (until the unit shuts off). 
This restores the earbuds to the factory defaults.
TWS must be connected to perform the reset, so neither of the earbuds should be off or in the charging case.
It also may be necessary to remove or forget the earbuds from the list of paired Bluetooth devices in order to pair again.