I have had my Casio WK-3500 for several years, and have a sustain pedal attached to it. Today I decided to restore the machine to it's factory settings. This went well until I realized that the sustain pedal no longer performs its function. Depressing the pedal no longer has any effect. I am pretty sure the pedal is in working order, as I was using it earlier today. Is there some sort of configuration I need to run to get the pedal up and running again? Thank you!