How to lock the screen of my Philips MP3 player? Accidental activation of the touch controls of your Philips MP3 player can be prevented by locking the screen. To lock/unlock the screen, press Power/Lock button. General information The volume control still works even if the screen is locked. Auto screen lock For convenience, automatic screen lock can be set. The screen dims and is automatically locked after a set period of time. Follow the steps below to set auto screen lock: From the Main Menu, go to Settings Select Display settings Choose Screen off timer and set the time To disable automatic screen lock, set the time as 0 min.