1. Key Action Issues:
- Sticky keys: Moisture or dirt can accumulate, causing keys to stick or become sluggish.
- Broken hammer shanks: With heavy usage, the wooden shanks that connect hammers to the keys may break.
2. Keybed Problems:
- Uneven key height: The keys may become misaligned, causing them to be at different heights.
- Swollen keys: High humidity can cause keys to expand and become difficult to play.
3. Action Regulation Issues:
- Improper let-off: When the keys are released, they should "let off" from the hammers at a specific point. Incorrect let-off can affect playability.
- Escapement issues: The hammer should "escape" from the strings slightly after striking. Incorrect escapement can hinder quick repetition of notes.
4. Hammer Problems:
- Worn hammers: Over time, the felt on hammers can wear out, affecting their ability to produce a clear tone.
- Loose hammer heads: The felt heads can become loose from the wooden hammer shanks, impacting sound quality.
5. String Breakage:
- Strings can break due to excessive tension, incorrect tuning, or external impacts, such as falling objects.
6. Soundboard Issues:
- Cracks: Changes in humidity, extreme temperature fluctuations, or structural instability can cause the soundboard to crack, affecting the overall tone.
7. Bridge Problems:
- Bridge pin issues: The pins that hold strings in place on the bridge can become loose, causing strings to buzz or go out of tune.
8. Pinblock Damage:
- Loose tuning pins: The pins that hold strings in place in the pinblock can loosen over time, causing strings to go out of tune easily.
9. Pedal Problems:
- Sustain pedal issues: The sustain pedal may not consistently lift or may get stuck, affecting the damper mechanism.
10. Structural Damage:
- Legs or frame damage: The legs or frame of the piano can get damaged due to accidents, mishandling during moving, or excessive weight placed on the instrument.
11. Climate-Related Issues:
- Humidity: Extreme changes in humidity can affect the wood, causing warping, cracking, or other structural problems.
- Temperature: Sudden temperature changes can cause various wooden parts to expand or contract, leading to tuning instability.
Regular maintenance, proper climate control, and care can help prevent or minimize these issues, prolonging the piano's life and performance.