Troubleshooting
SymptomUnable to connect
Please refer to the page on connection. Connecting
SymptomNo sound
Increase the volume on this unit or the device connected.
Check the sound output settings of the device.
Disconnect the plug of this unit from the terminal of the device and re-connect.
This may be remedied by enabling the USB host function on the smartphone.
The way to address this problem varies according to the model. Please try the steps below.
On the screen showing the list of apps, tap in sequence as follows: [Settings] 
[Useful tools] [Detect a USB device].
On the Home screen, tap in sequence as follows: [Menu icon] [Settings] [Device Connection] [USB Connectivity] [Detect USB device].
On the screen showing the list of apps, tap [Settings] [Additional Settings] in sequence and enable [OTG Connection].
* Items displayed on the screen are examples. Depending on the device used, displayed items may be different.
SymptomThe volume is low or the sound is unpleasant
Increase the volume on this unit or the connected device. If volume can be controlled on the app, increase the volume on the app as well.
Insert both of this unit into your ears securely.
Use a toothbrush to clean the audio output section. Cleaning Method
SymptomRemote control is not working
Some of the remote control functions may not work with some devices, OS and apps. This is not a malfunction.
SymptomUnable to skip back to the previous track
Press Multi-function button three times quickly during playback. The previous track or beginning of the current track will be played.
This feature may behave differently or it may not function correctly on some devices, OS or apps. When this occurs, operate the earphones on the connected device instead.
SymptomUnable to skip to the next track
Press Multi-function button twice quickly during playback. The next track will be played.
This feature may behave differently or it may not function correctly on some devices, OS or apps. When this occurs, operate the earphones on the connected device instead.
SymptomThe earphones fall off the ears easily
Wear the earphones correctly. Wearing the Earphones
SymptomThe sound is distorted
If volume can be controlled on the app, adjust it to a level such that the sound is not distorted, followed by adjusting the volume on this unit or the device.
SymptomThe other party cannot hear your voice
Check that the switch of the microphone is set to ON (left side), and make sure the microphone on the call/conference app in use is not turned off.
SymptomI want to use the earphones with my PC but no sound is heard
Refer to here. PC Connection Support