The RP55 can also be powered with the optional power supply. Connect the plug of the power supply to the power jack on the rear panel of the RP55. Connect the other end of the power supply to an AC outlet. Turn your amplifier(s) on and adjust the volume(s) to a normal playing level.
Furthermore, how do I reset my Digitech RP55?
Factory Reset:
To restore the factory settings of the Digitech RP55 multi-fx, you must connecting the power supply while simultaneously holding the Edit button, and when the display appears “–“, release the button and press the Store button. Warning! This procedure will erases all user-programmed data.