The use of the sustain pedal to cancel tone selections does not work, unless I shake the corresponding plug on the rear of the piano. I suspect that the mono phone jack (red, 1/4", 3-pin PCB mount) is defective. What advice should I know before attempting to replace the defective piece? Has anyone else experienced the same situation with the pedal response?
Take out the jack board and see whether the jack socket has broken the circuit board eyelets - simple solder fix.