1
YAMAHA
SILENT PIANO SERIES
b1-Silent, b2-Silent, JU109-Silent, JX113-Silent
MAINTENANCE HANDBOOK
Introduction
This is the service manual for the b1-Silent, b2-Silent, JU109-
Silent, JX113-Silent Pianos developed in 2006. In this series, the key
and pedal sensor systems are designed into the piano, and the tone
generator and input/output jacks have been unified into a compact
design that is incorporated into the switch box unit.
When the piano is played with its mute engaged, the key and pedal
sensors detect piano performance and relay this data to the tone
generator via jacks on the back of the switch box. The mute mech-
anism is controlled by the center pedal, which operates the shank
stopper with three wires.
Regarding maintenance, damper pedal sensor position adjustment
is now carried out using measurements, not with VR adjustment.
Since this manual mostly covers new content, please make sure
that you refer to both new and previous manuals when performing
maintenance.
Contents
Introduction ......................................................................................1
Unit Layout .......................................................................................2
Caution: Removing the Lower Front Board......................................2
Caution: When Tuning .....................................................................3
Attaching/Removing the Action ........................................................3
Silent Piano Adjustment Standards..................................................3
Shank Stop Maintenance/Adjustment Procedure ............................4
Some Tips on Shank Stopper Unit Motion .......................................5
Test Mode ........................................................................................6
Maintenance Mode...........................................................................7
Unit Block Diagram ..........................................................................8
