1, missing string: the piano string is broken, so it naturally bounces without vibration, so it is necessary to replace the string of the same model.
2. Breakdown of the clicker: When the external key is pressed, both ends of the key are lifted to push the clicker to transmit power to the hammer. If the rapper's connecting rod is broken and not reset, the screw is too loose, the process of transmitting power is blocked, and the hammer can't be pushed, which will also cause the keys of the fitness rack to be silent. Therefore, it is necessary to inspect and sort out rappers.
3. The vibration machine is seriously deformed: the piano leaks, the temperature difference keeps alternating, and the environment often changes, which will lead to the gradual deformation of the wood. When the deformation reaches a certain degree, the rapper is not in a straight line with the hammer and keys, or it is beyond the interconnection range, resulting in the silence of the keys. At this point, the deformed parts should be replaced.
4. Blocked by foreign objects: When the strings are attached by foreign objects, or the parts where the hammer hits the strings are blocked by foreign objects, the strings cannot vibrate or the hammer cannot touch the strings, so the strings cannot be played. Find the foreign body and clean it up.