Keywords: E171, sports headset, no sound, one side, one earbud, not work, no audio.
If sound only comes from one earbud, please:
1. Check to see if it is plugged tightly in case of loose connection.
2. If it is already plugged tightly, please check with other device. If the other device works, the problem will be the 3.5mm output of the first "not working" device.
If neither of the above works, please contact email@example.com for support and inform us WHAT DEVICE did you use with this headphones?