Use this guide to replace the volume knob and pitch bender if either of the knobs break, stop working, or get stuck and won't move.
Remove all the selector knob covers by pulling them off.
Using needle nose pliers, remove the washers from the four corner selector knobs.
Flip the device over. Using a Philips #2 screw driver, remove the fourteen 10.3 mm black screws holding the back panel in place.
Carefully flip the device to the front making sure you secure the face plate and the chassis together.
Rotate the device 180 degrees and carefully remove the face plate by slightly lifting the screen side towards you and then sliding the bottom out from under the keys.
Rotate the device 180 degrees, so that the motherboard is closest to you.
Remove the ribbon cable connecting the knobs to the mother board by gently wiggling and pulling it away from the motherboard.
Using a Phillips #2 screwdriver, remove the four 9.5 mm silver screws holding the knobs to the face plate.