With the factory settings, the SPD-SX PRO's power automatically switches off 20 minutes after you stop playing or operating the unit (with system program version 1.11 or later; 4 hours on earlier versions). If you don't need the power to turn off automatically, set "Auto Off" to "OFF". For details on the "Auto Off" settings, refer to “Configuring the Display, Screen Saver and Auto Off Function (OPTION)”.