Turn on the Xperia and then connect a cable.
For Xperia XA, connect a cable while the Xperia XA is turned off, and then turn on the Xperia XA.
If the Xperia still cannot be connected to the unit, check whether the latest version of Android OS is installed on the Xperia and then perform the following procedures on the Xperia.
For Xperia Z2/ZL2
Open Sound, then make a tick on Hi-res Audio via USB in Sound.
For Xperia Z3
Open Audio Settings from Sound, then make a tick on Hi-res Audio via USB.
For Xperia Z4/Z5
1. Open Apps.
2. Select Settings Device Connection .
3. Tap Detect USB device in USB Connectivity.
NOTE: If Xperia Z2/ZL2/Z3 models are updated to Android5.0 or later, there is no setting items mentioned above. These settings become unnecessary by updating the Android OS version.
[A] USB adaptor (not supplied) Use the USB adaptor that is sold separately for your smartphone. Connect it to the smartphone.
[B] Micro USB cable (not supplied).