So I was changing the trigger springs in my controller this evening and I noticed a small hole in the back of the controller, which I can only assume to be a reset perhaps?
What is this hole actually for?
You're correct, according to Sony's documentation, it is the reset button.
These are the instructions on how to reset the controller taken from the documentation:
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:
- Turn off the PlayStation 4.
- Locate the small reset button on the back of the DualShock 4 near the L2 shoulder button.
- 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.
- After resetting the controller, re-pair the controller with the PS4 by connecting the USB cable to the controller and the system, and turn the PS4 on.
- Press the PS button to log in to the PS4