Press and hold Tweak while pressing the A button to get into the System menu.
Press + several times until you reach the lowest line. Turn the encoder to the right of the display a couple of clicks until you can see “FACTORY SOUNDSET? [Y]” Press Yes. This plays the factory sound set back in.
Adjust the other settings in the menu to the following values:
MIDI CHANNEL: Omni
Master Tuning: 440 Hz
Transpose: +00
Pitch Bend Range: 02
Control X: 002
Tx Edits: Off
Tx Program Change: On
TX Aftertouch: On
TX Keys/Controls: On
Local Control: On
Device ID: 000
Line In: Off
Input Gain: +18dB
Input Low-cut : Off
Mic Power: On
Freeze Threshold: 002