Unit Connection Diagram - Yamaha GB1KS Maintenance Handbook

・SW Box and Sensor unit communication test
When the test starts, the two units (Switch Box and Key Sensor) automatically
communicate with each other.
C major chord plays if communication is successful.
C minor chord plays if communication is unsuccessful.
The "Black Key Etude (Chopin)" plays continuously while the test is in progress.
Automatic communication between the units by the test startup displays the status with a chord sound.
・AD test
Detects reverb knob rotation and damper pedal depth, and then produces a chromatic scale.
During the test,
Rotating the reverb knob clockwise produces a chromatic scale from low to high (counter
clockwise rotation produces a chromatic scale from high to low).
Pressing the damper pedal produces a chromatic scale from low to high (releasing the pedal
produces the scale from high to low).
■Checking versions and types
Please refer GPS-GB1 Service manual PP068615 page 21 and 22.

Unit Connection Diagram

Switch Box
AC Adapter
Key Sensor Unit
DM sheet
Key Sensor Sheet
Shift Pedal Damper Pedal
Sensor Sensor
Fig.21
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