Or the earphone battery is dead, and the box's battery can be recharged. The reason for this battery failure is that the box is not usable, and it is recommended to take it for repair or replacement.
If you do not give up, you can change a charging cable to try.
Or change to the usb interface output of the computer to charge, ensure that the jack is in good contact, if it cannot be charged, repair or change the box according to the above.