Try factory reset for Privia PX320:
Perform the following procedure when you want to
return the digital piano's stored data and settings to
their initial factory defaults.
1. While the digital piano is turned off, hold
down the RHYTHM, and FUNCTION buttons
as you press the POWER button to turn on
power.
• This will initialize the digital piano and then perform
system setup.
NOTE
• It will take some time for the digital piano initialization
procedure complete. During that time, the display
contents will be different from those that normally
appear when you turn on power (page E-10).