Digital pianos approximate the sound, dynamics and feel of an acoustic piano while offering a significantly larger range of tones. An acoustic piano makes sound when the key-hammers hit the strings. A digital piano makes sound when a key-contact strikes the contact strip. The contact strip sends an electrical charge to a signal processor, which triggers the sound. If the keys are loose, sticking or dirty, it can reduce playability and interfere with the sound. Removing the keys allows you to examine, fix, and clean the contacts and contact strip.
Identify which keys you want to remove. Play each key from left to right. If a key is sticking, loose, or making a crackling sound, stick a piece of colored electrical tape on it. Once you’ve opened up the digital piano housing, you can’t troubleshoot the piano.
Turn off the power and remove the power adapter.
Unfasten the screws holding the top panel of the piano chassis to the base. The number of screws that you need to remove varies depending on make and model. There is typically a series of between four and eight screws along the top edge of the piano. Use a small Phillips screwdriver to remove these. Slide the top panel off and place it to the side.
Place two cushions on your work bench, far enough apart that you can rest the edges of the piano on them. Place the piano face-down so that the edges rest on the cushions. This prevents the keys and controls from getting squashed against the work bench.
Unscrew the bottom panel with a small Phillips screwdriver. This exposes the contact board and circuit boards, leaving just the molded sides in place.
Remove the plastic connector plugs from the circuit board. Stick a piece of colored electrical tape to the socket on the circuit board where the plug was attached so that you know exactly where to re-attach it.
Place the digital piano face-up on the work bench. Lift the keyboard assembly out of the digital piano housing. Since you removed the top panel, there is enough room to fit your hands down either side of the keyboard assembly. With some models of digital piano, such as the Kurzweil SP4-8 which has 88 weighted-keys, the assembly can be quite heavy.
Place the keyboard assembly face-up on your work bench. Hook your finger around the back of each key that has a piece of tape on it. Lift the key up from the back and slide it forward. Place the keys down in the order that they appear on the digital piano.
Spray a plastic-safe contact cleaner onto the contact strip before replacing the keys.