Piano key makes no sound or a weak sound

Symptoms

• Pressing the key produces no sound at all
• Note sounds much quieter than surrounding keys
• A dull thud instead of a musical tone
• Problem is limited to one or two adjacent keys

Likely causes

• CommonBroken or badly out-of-adjustment hammer mechanismOn acoustic pianos, a part in the action linking key to hammer can slip or break, so the hammer never reaches the string.
• PossibleBroken stringA snapped string will produce no sound or a strange overtone from the remaining strings for that note.
• CommonDigital piano key contact or sensor failureOn digital pianos and keyboards, a worn rubber contact under the key stops sending the electronic signal.
• PossibleForeign object jammed in the actionSomething lodged between action parts can block the hammer's travel.
• Less commonDamper not lifting properlyA damper that fails to lift can mute the string even when it's struck.

What to do

1. Press the key a few times at different speeds and note whether it's completely silent or just quiet.
2. On a digital piano, check the volume and local control settings, and try a different sound/patch to rule out a settings issue.
3. For digital pianos, gently vacuum around and under the key area for dust without disassembling anything.
4. On an acoustic piano, look inside (top open, careful not to touch strings or action) for anything visibly broken or a hammer resting at an odd angle.
5. Try the same key an octave up or down to confirm it's isolated to that one note.
6. Avoid pressing hard or repeatedly forcing the key, which can worsen a broken part.
7. For a digital keyboard still under warranty, contact the manufacturer before opening the case.

Tools and parts

• Flashlight
• Small vacuum with brush attachment (digital pianos)

When to call a pro

This almost always needs a professional: a piano technician for acoustic action or string issues, or a keyboard repair tech or manufacturer service for digital pianos.

Safety