The sound of your Bluetooth device cannot be heard on this system.
Turn up the volume on your Bluetooth
device first, and then adjust the volume using VOLUME +/.
Severe hum or noise
If there are obstacles between the system and your Bluetooth device, remove or avoid the obstacles.
If there is equipment that generates electromagnetic radiation, such as a wireless LAN, other Bluetooth device, or a microwave oven nearby, move them away.
Turn down the volume of the connected Bluetooth device.
The sound from the Bluetooth headphones is distorted.
Turn down the volume of the system using VOLUME . If your headphones have a volume control, also adjust the volume using the headphone’s volume control.
Press DSGX on the unit repeatedly until “DSGX OFF” appears.
Press EQ repeatedly to select
“BASS” or “TREBLE,” and then press PRESET repeatedly to turn down the level.
USB device
Are you using a supported USB device?
If you connect an unsupported USB device, the following problems may occur. See “Playable USB devices and Bluetooth devices” (page 115) for the supported device types.
The USB device is not recognized.
File or folder names are not displayed on this system.
Playback is not possible.
The sound skips.
There is noise.
“Over Current” appears.
A problem has been detected with the
level of electrical current from the 
(USB) port . Turn off the system and
remove the USB device from the 
(USB) port . Make sure there is no problem with the USB device. If this display pattern persists, contact your nearest Sony dealer.
There is no sound.
The USB device is not connected correctly. Turn off the system, then reconnect the USB device and check if “USB MEMORY” appears.
The sound is distorted.
The bit rate used when encoding the files was low. Send files encoded with higher bit rates to the USB device.