Casio Privia PX-720 Troubleshooting guide

ELECTRONIC KEYBOARD
(without price)
PX-720/PX-720C
SEP. 2007
Ver. 6 : Oct. 2015
PX-720C
INDEX

CONTENTS
SPECIFICATIONS ------------------------------------------------------------------------------------------ 1
BLOCK AND WIRING DIAGRAM --------------------------------------------------------------------- 2
PCB LAYOUT ----------------------------------------------------------------------------------------------- 3
CIRCUIT DESCRIPTION --------------------------------------------------------------------------------- 4
PRINTED CIRCUIT BOARDS -------------------------------------------------------------------------- 5
DISASSEMBLY --------------------------------------------------------------------------------------------- 7
DIAGNOSTIC PROGRAM ------------------------------------------------------------------------------18
EXPLODED VIEW ----------------------------------------------------------------------------------------21
PARTS LIST ------------------------------------------------------------------------------------------------23
SCHEMATIC DIAGRAMS -------------------------------------------------------------------------------27

– 1 –
SPECIFICATIONS
Keyboard: 88-key piano keyboard, with Touch Response
Maximum Polyphony: 128 notes
Tones: 11
• Layer (excluding bass tones)
• Split (Low-range bass tones only)
Effects: Brilliance (−3 to +3), Reverb (4 types), chorus (4 types), Acoustic Resonance
Metronome:
• Beats: 0, 2, 3, 4, 6
• Tempo Range: 20 to 255
Duet: Adjustable tone range (−1 to +2 octaves)
Music Library:
• Number of Songs: 60
• Song volume: Adjustable
• Part On/Off: L, R
Recorder:
• Functions: Real-time recording, playback
• Number of Song: 1
• Number of Tracks: 2
• Capacity: Approximately 5,000 notes total
• Recorded Data Protection: Built-in flash memory
Pedals: Damper, soft, sostenuto
Other Functions:
• Touch Select: 3 types, Off
• Transpose: 2 octaves (−12 to 0 to 12)
• Tuning: A4 = 440.0 Hz ±99 cents (variable)
• Operation Lock
MIDI: 16-channel multi-timbre receive
Inputs/Outputs:
• PHONES jack: Stereo standard jacks × 2
Output impedance: 170Ω
Output Voltage: 5.6V (RMS) MAX
• Power: 12V DC
• MIDI OUT/IN terminals
• Pedal connector
Speakers:
φ
12cm × 2 (Output 8W + 8W)
Power Requirements: AC Adaptor: AD-12
Power Consumption: 12V 18W
Dimensions: Digital Piano and Stand: 137.1 (W) × 29.8 (D) × 79.2 (H) cm (54 × 11 3/4 × 31 3/16 inch)
Weight: Digital Piano and Stand: approximately 32.0 kg (70.5 lbs)

– 2 –
BLOCK AND WIRING DIAGRAM
RAM (64Mbit)
IC2
Reset IC
IC1
RESET
12MHz
SAD0 ~ SAD12,
SDBA0,SDBA1
SDD0 ~ SDD15
D8 ~ MD15
Power Amplifier
IC201
Filter
IC205
FLASH (128Mbit)
IC6
ROM (16Mbit)
IC7
A1 ~ A20
D0 ~ D15
MA0 ~ MA3
MD0 ~ MD15
KEY CONTROLLER
IC11
Keyboard
Power Supply Circuit
IC202,Q206,Q207
(12V)
VA12
(5V)
VD5
(5V)
VE5
(12V)
VC
Speakers
(L) (R)
Main
Volume
CONSOLE PCB
(M681-CNA1)
CONSOLE PCB
(M406-CNA4)
Keyboard PCBs
(MCPZ-KYA1/KYB2/KYA3)
SUB PCB
(M408-PSA1)
CONSOLE PCB (M681-CNA3)
CONSOLE PCB
(M681-CNA2)
MAIN PCB (M408-MDA1)
Buttons
SI0 ~ SI10 FI0 ~ FI10
LOUT ROUT
KC0 ~ KC7
MPU
IC5
Control signal
Power
Switch
DAC
IC10
CN9CN13CN2
CN601CN211
CN605
CN14
CN602
CN206
CN203
CN207
CN603
CN15
CN604
CN607
CN606 CN201
CN209
CN204

– 3 –
PCB LAYOUT
PCB Components
MAIN PCB M408-MDA1 MPU, Reset IC, RAM(64Mbit), FLASH memory(128Mbit),
ROM(16Mbit), DAC, Key controller
SUB PCB M408-PSA1 Power supply circuit, Filter, Power amplifer
Console PCBs M681-CNA1 Button, Main volume
M681-CNA2 Phones jack
M681-CNA3 DC 12V terminal, MIDI OUT/IN terminals
M681-CNA4 Power lamp
Rear
M408-MDA1 PCB
M681-CNA1 PCB
M68
1-
C
NA4 P
CB
M681-CNA2 PCB
M681-CNA3 PCB
M408-PSA1 PCB

– 4 –
CIRCUIT DESCRIPTION
KEY MATRIX
NOMENCLATURE OF KEYS
KC0 KC1 KC2 KC3 KC4 KC5 KC6 KC7
FI0 A0A0#B0C1C1#D1D1#E1
SI0 A0A0#B0C1C1#D1D1#E1
FI1 F1F1#G1G1#A1A1#B1C2
SI1 F1F1#G1G1#A1A1#B1C2
FI2 C2#D2D2#E2F2F2#G2G2#
SI2 C2#D2D2#E2F2F2#G2G2#
FI3 A2A2#B2C3C3#D3D3#E3
SI3 A2A2#B2C3C3#D3D3#E3
FI4 F3F3#G3G3#A3A3#B3C4
SI4 F3F3#G3G3#A3A3#B3C4
FI5 C4#D4D4#E4F4F4#G4G4#
SI5 C4#D4D4#E4F4F4#G4G4#
FI6 A4A4#B4C5C5#D5D5#E5
SI6 A4A4#B4C5C5#D5D5#E5
FI7 F5F5#G5G5#A5A5#B5C6
SI7 F5F5#G5G5#A5A5#B5C6
FI8 C6#D6D6#E6F6F6#G6G6#
SI8 C6#D6D6#E6F6F6#G6G6#
FI9 A6A6#B6C7C7#D7D7#E7
SI9 A6A6#B6C7C7#D7D7#E7
FI10 F7F7#G7G7#A7A7#B7C8
SI10 F7F7#G7G7#A7A7#B7C8
F#3G#3 A#3 C#4D#4 F#4G#4A#4 C#5D#5 F#5G#5 A#5
F3 G3 A3 B3 C4 D4 E4 F4 G4 A4 B4 C5 D5 E5 F5 G5 A5 B5 C6
D#3
C2 D2 E2 F2 G2 A2 B2 C3 D3 E3 B6A6G6F6E6D6 C7
C#3A#2G#2F#2D#2C#2
C1 D1 E1 F1 G1 A1 B1A0 B0
A#1A#0 G#1F#1D#1C#1 A#6G#6F#6D#6C#6
B7A7G7F7E7D7 C8
A#7G#7F#7D#7C#7
BUTTON MATRIX
SWB SWC SWD SWE
SI0
SONG
/
MODERN METRONOME
SI1 L / R RECORDER CLASSIC
TONE/
SETTING

– 5 –
PRINTED CIRCUIT BOARDS
Main PCB M408-MDA1
Sub PCB M408-PSA1

– 6 –
Console PCB M681-CNA1 Console PCB M681-CNA2
Console PCB M681-CNA3 Console PCB M681-CNA4

– 7 –
DISASSEMBLY
■ To remove main body and speaker box.
*The screws come with the cap.
*Do not forget to attach the screw caps when assembling.
1. Remove the Connector and Pedal cord.
2. Remove 2 screws and then the Pedal unit
3. To damage neither the floor nor the main body, the main body is put on the mat or the blanket, etc.
4. Remove 8 screws and take off the left and right outer side covers.
ConnectorPedal cord Screws
Pedal unit
Main body
Speaker box

– 8 –
■ Speaker box disassembly
1. Remove the 20 screws and then the back of the speaker box.
2. Remove the 4 screws for each speaker and then take out the speakers (left and right).
■ Removing the T-BRD-UNIT.
1. Remove 18 screws and then the T-BRD unit.
T-BRD unit