When I connect a DualShock4 controller to the player via USB cable, the device cannot be operated.

By design, the DualShock4 wireless controller is meant to be connected to the Blu-ray player via Bluetooth only. The device cannot be operated by a DualShock4 wireless controller that is connected to the player via USB cable.

For the pairing procedure, try the following steps.

1. From the Blu-Ray Disc player Home Screen, select Setup.
2. Select Bluetooth Settings.
3. Verify that Bluetooth Mode is ON.
4. Go back to Setup and select System Settings.
5. Select DUALSHOCK4 wireless controller.
6. After selecting the Register Controller menu, press and hold the Share and PlayStation buttons for up to 8 seconds on your DualShock4 wireless controller. The controller should flash white light from the light bar.

A confirmation message will appear on the screen, saying "Wireless Controller is connected" when the pairing is successful.