If your controller won't pair, won't respond, or is displaying a flashing light, please follow the instructions on how to reset the controller:
Step 1: Turn off the PlayStation 4.
Step 2: Locate the small reset button on the back of the SCUF 4PS near the L2 shoulder button.
Step 3: Use a small, unfolded paper clip or something similar to push the button (the button is inside a tiny hole). Hold the button down for a couple of seconds and release.
Step 4:After resetting the controller, re-pair the SCUF with the PS4 by connecting the USB cable to the controller and the system, and turn the PS4 on.
Step 5: Press the PS button to log in to the PS4.