Check the following:
- The supplied USB cable is used for the connection.
- The cable connection is secure.
- Make sure that the USB AC adaptor is firmly connected to the AC outlet.
- When charging the headset through a USB port on a computer, try the following as well:
- Make sure that the computer is turned on.
- If the computer is equipped with multiple USB ports, use another port.
- Connect the headset directly to the computer without using a USB hub.
- If the computer is in Standby (Sleep) or Hibernate mode, place it back to normal mode.
- If the computer is running on Windows 8.1, use Windows Update to update the operating system.