Repair: Weird clicking sound on Zoom G2.1NU's Pedal

Did you hear some clicking sound when you use your G2.1NU's built-in expression pedal? If yes, stop using it. Investigate. There is a possibility the the potentiometer inside is hitting the end of its wiper when the pedal is pressed and unpressed. This will limit the gear inside. Worse, it could the damage the gear and potentiometer inside.

I had this problem this morning and this is how I solved it.

Remove all the screws.
Open the case until you see the electronics boards inside.
Encircled in red is the potentiometer's location.


Remove the two screws to loosen up the potentiometer and the gear


Readjust the gear of the potentiometer.Do a trial and error until the clicking sound disappear.
Reassemble the unit.
Do a pedal calibration. Press and hold "Pedal Assign" thne on the unit.
Plug in your guitar.
Enjoy.