> When in Trouble > Troubleshooting
Troubleshooting
SymptomUnable to pair
When pairing, make sure the BLUETOOTH device is within 1 m of the System.
Operate the BLUETOOTH device to connect.
Turn on the BLUETOOTH device and enable pairing.
Delete the pairing information on the BLUETOOTH device list and perform pairing again.
Perform operations after setting the BLUETOOTH function of the connected device to OFF and then to ON again.
Perform operations after turning off the connected device and on again.
Refer to the page on connection. Connecting (Power On)
Check whether the System is connected to another device. Turn off the BLUETOOTH settings of other devices and enable pairing with the desired device.
SymptomThe indicator flashes and connection cannot be established
Turn on the BLUETOOTH device, enable its Bluetooth function and select the System from the BLUETOOTH device list.
SymptomUnable to turn on the power
Re-charge unit. Charging
SymptomUnable to charge
Make sure that the USB cable is plugged in all the way.
Please charge within the charging temperature range (5 °C (41 °F) to 35 °C (95 °F)).
SymptomAfter connecting to the System, the BLUETOOTH device connected does not function immediately
Depending on the BLUETOOTH device connected, even when the indicator is flashing slowly after connecting to this System, the BLUETOOTH device may not function immediately due to the time lag in the connection operation. Wait for a few seconds and try operating again.
SymptomThe System does not work correctly
While the power is turned on and the System is not connected to a BLUETOOTH device, press Multi-function button and 
buttons for 10 seconds or more. The indicator flashes twice and the System is initialized.
SymptomThe sound is choppy and there is noise
Use the connected device in a position or orientation that allows for the most stable communication. The sound tends to be interrupted when the System is covered with the hands.
Try reducing the number of apps running on the BLUETOOTH device connected.
Charge the System. Charging
SymptomThe volume is low or the sound is unpleasant
Increase the volume on the System or the BLUETOOTH device connected.
SymptomThe sound is distorted
Adjust the volume on the BLUETOOTH device connected so that there is no distortion, and then adjust the volume on the System.
Re-charge unit. Charging
SymptomThe noise canceling function is not very effective
Check that the noise canceling function is turned on. Operating the System
The noise canceling function is less effective depending on the type of noise.
When the Sidetone is switched to On, the noise canceling function may not be very effective (the Sidetone function takes priority during a call). The Sidetone function can be turned on/of by using the app. For more details about the app, please refer to: About the JVC Headphones App
SymptomEffect of the ambient sound function is weak
Check that the ambient sound function is turned on. Operating the System
When the playback volume of the music is loud, it may be difficult to feel the effect. Lower the playback volume.
When the Sidetone is switched to On, the ambient sound function may not be very effective (the Sidetone function takes priority during a call). The Sidetone function can be turned on/of by using the app. For more details about the app, please refer to: About the JVC Headphones App
SymptomRing tone is soft and cannot be heard
The ring tone may not be heard from the headphone if the silent mode of the BLUETOOTH device (iPhone/smartphone/tablet) is turned on. Turn off the silent mode on the BLUETOOTH device. Alternatively, to use it in the silent mode, enable the device to detect incoming calls (via the vibration feature on the device, etc.) and use the earphones to answer the call. When there is an incoming call, the call may start on the BLUETOOTH device instead if you answer the call using the device.
SymptomMusic or voice calls cannot be heard
Delete the pairing information on the BLUETOOTH device list. Perform pairing after turning off the connected device and on again (or after rebooting).
SymptomUnable to connect to second Bluetooth device when multipoint is in use
Change the Bluetooth setting of the first Bluetooth device to “Off” before connecting to the second device.
SymptomUnable to connect when using the call/conference application on the computer
Refer to here. PC Connection Support
SymptomYou cannot hear the other party’s voice and vice versa while using the call/conference application by connecting to a computer
There is a way to set the audio input/output destination on the computer or call/conference application. Open the Settings menu and select “Headset (JVC HA-S75N Hands-Free)” or “JVC HA-S75N Hands-Free”, etc. (the item displayed may differ depending on the OS and application). For details, refer to the instruction manual of the computer or call/conference application.
SymptomSound quality for videos and music is poor and the sound mode cannot be changed when connected to a computer
There is a way to set the audio input/output destination on the computer or the music and video playback application. Open the Settings menu and select “Headphone (JVC HA-S75N Stereo)” or “JVC HA-S75N Stereo”, etc. (the item displayed may differ depending on the OS and application). For details, refer to the instruction manual of the computer or the music and video playback application.