User Guide

HD 4.50BTNC | 31
Troubleshooting
Troubleshooting
Problem Possible cause Possible solution Page
Headphones
cannot be
switched on
Battery is empty Charge the headphones 13
Battery is completely
exhausted/worn out
Visit an authorized
Sennheiser service center
for battery replacement
No audio signal Headphones are not
paired with your device
Check if the headphones
are paired. If necessary,
pair the headphones with
the device again
14
Volume too low Increase the volume 20
Headphones are
switched off
Switch the headphones on 19
Headphones
cannot connect
Pairing does not work Check if your smartphone
supports the HFP or HSP
Bluetooth profile
Smartphone is
switched off
Switch your smartphone
on
Bluetooth is
deactivated on your
smartphone
Activate Bluetooth on your
smartphone
Headphones
do not respond
to any button
press
Headphones are not
functioning properly
Restart the headphones by
switching them off and on
again.
19
No audio signal Headphones are not
paired with your device
Check if the headphones
are paired. If necessary,
pair the headphones with
the device again
Volume too low Increase the volume
Headphones are
switched off
Switch the headphones on
Headphones
do not
automatically
go to pairing
mode
Headphones must have
been paired previously
to some devices
Switch the headphones
off and press the power
button for 4 seconds
16
If you encounter a problem that is not listed in the table, or if the solutions
provided do not work, please contact an authorized Sennheiser service partner
for assistance.
To find a Sennheiser service partner in your country, visit www.sennheiser.com.