Casio AP21 Service Manual

AP-21

INDEX

Ver. 1 SEP. / 2002

MAY 1999

AP-21

ELECTRONIC KEYBOARD

CONTENTS

Safety Notice...................................................................................... 1

Specifications .................................................................................... 2

Block Diagram ................................................................................... 3

PCB Layout ........................................................................................ 4

Disassembly Instructions ................................................................. 5

Circuit Description ............................................................................ 8

Major Waveforms.............................................................................10

Troubleshooting .............................................................................. 11

Wiring Diagram ................................................................................ 14

Exploded View ................................................................................. 15

Parts List .......................................................................................... 16

Schematic Diagrams ....................................................................... 19

SAFETY NOTICE

CAUTION!
Danger of explosion if battery is incorrectly replaced.
Replace only with the same of equivalent type recommended
by the appliance manufacturer.Discard used batteries
according to manufacturer's instructions.

— 1 —

SPECIFICATIONS

GENERAL

Number of keys: 88
Polyphonic: 32-note
Preset tones: Piano-1, Piano-2, Electric Piano, Harpsichord, Vibraphone, Pipe Organ, Strings,

Choir.

Keyboard Controls: Touch sensitivity (Initial touch: Light/Middle/Heavy),

Tuning curve (Standard/Electric piano/Flat),

Baroque pitch (On/Off)
Pedals: Soft/Sostenuto, Damper
Effects: Reverb (Room, Stage, Hall-1, Hall-2), Chorus, Tremolo, Brilliance
Transpose: F# - C - F
Tuning control: A4 = 440Hz ± 50 cents
Demonstration tunes: 1: Polonais "Héroïque" (F.F. Chopin) 5: CASIO original

2:

Frühlingslied Op. 62-6 (F. Mendelssohn)
3: CASIO original 7: CASIO original
4: Harmonious blacksmith (G.F. Händel) 8: CASIO original

Memory: Real-time recording [Number of Songs: (A and B), Capacity: Approx. 3,000

notes total]
Backup Battery [Built-in lithium battery: BR2330, Battery life: Approx. 5years]

Terminals: LINE IN Jack [Input impedance: 30KΩ, Sensitivity: 200mV]

LINE OUT Jack [Out put impedance: 22KΩ, Output voltage: 2.0V (rms) MAX],
Phone Jack [6.3ø, stereo], MIDI jack (IN, OUT, THOUGH)

Speakers: 16cm dia. Approx. 20W input Rating: 2 pcs.
Power source: AC source (120V, 230/240V)
Power consumption: 48W (120V AC), 62W (230/240V AC)
Dimensions: 7-3/4" (H) × 54 (W) × 18 - 1/2" (D)

198mm (H) × 1370mm (W) × 470mm (D)

Weight: 36.4kg (80.3 lbs) /45.5kg (100.3 lbs) with stand

6:

jesus, Bleibet Meine Freude (J.S. Bach)

Nomenclature of keys

A1# A2#G2#F1# F2#D1#C1#AD# A7#G7#F7#

G1#

B0 A2F1 F2G1 G2A1 B1 B2C1 D1 C6E1 E2 G6E6 F6 A6 B6 C7D6 E7 F7D7C2 C8B7A7

A0

C2# D2# C6# D6# G6#F6# A6# C7# D7#

D2 G7

— 2 —

MIDI

OUT IN THROUGH

BLOCK DIAGRAM

Sound Source Rom

(3M-bit)

LSI 6

MX23C2410MC-12CA58

LEDS

Keyboard

FI0~FI10
SI0~SI10

Key touch LSI

LSI 10

HG52E35P

Gate array

L1~L18

UPD65005GF

KI0
KI3

KC0~
KC7

LSI 301

-419

KC0

~

KC4

P10, P12~P16,
P93, P94, P97

P70~P77

P12~P14

~

Pedal
unit

Damper

SS

SF

CPU

LSI 1

HD6435328RC13F

Mute signal

D0~D7

RD0~RD15

RA0~RA22

LSI-S

LSI 7

HG51B155FD-1

ED0~
ED15

EA0~
EA14

SOLP
SOLM

BOK, WOK1

SORP
SOLM

DAC

LSI4,5

UPD6376GS-E1

DAC

LPF

IC 408

IC 411

LPF

Mute signal

Main
volume

MIXER

IC 406

Power
amp.
IC 405

Console

BRILLIANCE

System ROM

LSI 2

2M-bit

LH532KU3

Working strage

LSI 3
SRAM 256K-bit
TC55257DFL-70L

A0~A14

Effector RAM

256K-bit

LSI 8, 9

TC55257DFL-70L

A0~A16

— 3 —

Reset signal

Power supply
circuit

Reset IC

IC 5

VDD (+5V)
AVDD (+5V)
AVCC (+15V)
AVFF (-15V)

PCB LAYOUT

PS3M

ON
OFF

POWER

PS4M

Main PCB

Sub PCB

MIN MAX

PCB

PS12

MA1M

PS2M

VOLUME

TRANSPOSE/

DIGITAL

TUNE/MIDI

EFFECT

CHORUS REVERB

REVERB2

REVERB1

PIANO E.PIANO

TONE

HARPSI­CHORD

MEMORY

DEMO

SONG A

PIPE

STRINGS

ORGAN

START/

STOP

SONG B

RECORD

CN1MCN2M

KY1M KY2M KY3M

Components

MA1M

JCM358-

CPU, LSI-S, Sound Source ROM Working storage
RAM, Effect RAM Reset IC, DAC, Key Controller

PS2M

Filter, Lineout Amp., Power Amp. Power supply cir­cuit. MIDI input/output.

AP-21

Console PCB

Other PCBs

CN1M
CN2M
PS12
PS3M
PS4M

LEDs, Buttons, Gate array
Main Volume
Fuse
Head phone Jack
Power lamp

— 4 —

DISASSEMBLY INSTRUCTIONS

1. Removal of top board

1-1. Remove 6 screws affixing the top board on the back.
1-2. Slide the top board forward and remove it from the main

unit.

2. Removal of keyboard cover

2-1. Lift up the keyboard cover full open position.
2-2. Unscrew the L-shaped stopper metal located on the inner

left corner.

2-3. Lift up the keyboard cover gear from the opening where

stopper metal is fixed then remove the keyboard cover.

— 5 —

3. Removal of console panel

3-1. Remove screws affixing both ends of the console panel.
3-2. Disconnect connector CD on PCB MA1M, connector CF on PCB PS2M, and transformer grounding

wire.

3-3. Lift the console panel and turn it over and remove the power switch, which is affixed by 2 screws.

Then remove the side panel.
Caution: Be careful not to scratch the side panels.

Earth cable Screw Connector (CD) Connector (CD)

4. Removal of front cover

4-1. Remove 6 screws from the front end of the lower case.
4-2. Lift the front cover and remove the pilot lamp that is affixed

by 2 screws. Then remove the front cover.

5. Removal of keyboard unit

5-1. Disconnect connector CA on the PCB MA1M.
5-2. Remove 23 screws that affix the keyboard unit

(16 on the bottom of the case and 7 on the
keyboard unit).

5-3. Lift and remove the keyboard unit.

screws

Front cover screws

Keyboard screws

Bottom

Keyboard screws

— 6 —

6. Removal of keys

6-1. While plying the side partition plastics with tweezers, lift

the edge of the key toward front.

7. Removal of keyboard PCB

7-1. Lay the keyboard so that keyboard PCBs face upward.
7-2. Remove screws on keyboard PCBs (10 screws on PCBs

KY1M and KY3M, 12 screws on KY2M).

7-3. Unsolder the cable.

8. Totes on replacing the main PCB.

A lithium battery is set on the main PCB for memory protection.
When you replace the main PCB, disconnect the jumper to open battery circuit.
Since there is no jumper on a new main PCB, be sure to set a jumper.

jumper

— 7 —

KEYMATRIX

Second contact First contact

CIRCUIT DESCRIPTION

FI

2

KC0 KC1 KC2 KC3 KC4 KC5 KC6 KC7
FI0 A0 1 A0 # 1 B0 1 C1 1 C1 # 1 D1 1 D1 # 1 E1 1
SI0 A0 2 A0 # 2 B0 2 C1 2 C1 # 2 D1 2 D1 # 2 E1 2
EI1 F1 1 F1 # 1 G1 1 G1 # 1 A1 1 A1 # 1 B1 1 C2 1
SI1 F1 2 F1 # 2 G1 2 G1 # 2 A1 2 A1 # 2 B1 2 C2 2
FI2 C2 # 1 D2 1 D2 # 1 E2 1 F2 1 F2 # 1 G2 1 G2 # 1
SI2 C2 # 2 D2 2 D2 # 2 E2 2 F2 2 F2 # 2 G2 2 G2 # 2
FI3 A2 1 A2 # 1 B2 1 C3 1 C3 # 1 D3 1 D3 # 1 E3 1
SI3 A2 2 A2 # 2 B2 2 C3 2 C3 # 2 D3 2 D3 # 2 E3 2
FI4 F3 1 F3 # 1 G3 1 G3 # 1 A3 1 A3 # 1 B3 1 C4 1
SI4 F3 2 F3 # 2 G3 2 G3 # 2 A3 2 A3 # 2 B3 2 C4 2

1

KC
SI

LSI

HG52E35P

FI5 C4 # 1 D4 1 D4 # 1 E4 1 F4 1 F4 # 1 G4 1 G4 # 1
SI5 C4 # 2 D4 2 D4 # 2 E4 2 F4 2 F4 # 2 G4 2 G4 # 2
FI6 A4 1 A4 # 1 B4 1 C5 1 C5 # 1 D5 1 D5 # 1 E5 1
SI6 A4 2 A4 # 2 B4 2 C5 2 C5 # 2 D5 2 D5 # 2 E5 2
FI7 F5 1 F5 # 1 G5 1 G5 # 1 A5 1 A5 # 1 B5 1 C6 1
SI7 F5 2 F5 # 2 G5 2 G5 # 2 A5 2 A5 # 2 B5 2 C6 2
FI8 C6 # 1 D6 1 D6 # 1 E6 1 F6 1 F6 # 1 G6 1 G6 # 1
SI8 C6 # 2 D6 2 D6 # 2 E6 2 F6 2 F6 # 2 G6 2 G6 # 2
FI9 A6 1 A6 # 1 B6 1 C7 1 C7 # 1 D7 1 D7 # 1 E7 1
SI9 A6 2 A6 # 2 B6 2 C7 2 C7 # 2 D7 2 D7 # 2 E7 2

FI10 F7 1 F7 # 1 G7 1 G7 # 1 A7 1 A7 # 1 B7 1 C8 1
SI10 F7 2 F7 # 2 G7 2 G7 # 2 A7 2 A7 # 2 B7 2 C8 2

— 8 —

POWER SUPPLY CIRCUIT

The power supply circuit generates five voltages as shown in the following table.

Name Voltage For operation of

VDD +5 V CPU, Reset IC, DSP, Sound source ROM, Working storage RAM, Effect RAM,

Key touch LSI, Gute array, LEDs
AVDD +5 V DAC
A VCC +15 V Filter, Mixer

AVFF -15 V Filter, Mixer

— 9 —

MAJOR WAVEFORMS

A 1ms

1

2

˜˜

CH1 .2V CH2 .2V

1 Filter output L-ch CF connector pin 2
2 Filter output R-ch CF connector pin 1

Tone : Piano 1
Key : A4

A 2ms

6

CH1

CH2

CH1

A 20 µs

3

4

5

˜

CH1 5V CH2 5V

CH3 5V

3 Key scan signal KC0 CA connector pin 20
4 Key scan signal KC1 CA connector pin 19
5 Key scan signal KC2 CA connector pin 18

CH1

CH2

CH3

7

8

CH1 5V CH2 5V

CH2 5V

6 Button scan signal L24 UPD65005GF-419 pin 53
7 Button scan signal L25 UPD65005GF-419 pin 54
8 Button scan signal L26 UPD65005GF-419 pin 55

CH2

CH3

— 10 —

1. No power

TROUBLESHOOTING

Check fuse F401.

Is F401 blown up?

No

Check fuses F402, F403, and
F404.

Are the fuses blown up?

No

Measure output voltages of
the transformer.

Yes

Replace main PCB. No

Are the voltages 21.6 V AC

and 8.4 V AC?

Check the power switch.

Yes

Replace F401.

Yes

Replace F402, F403, and
F404.

Is it OK?

Yes

Check position of voltage
selector.

Is it OK?

Yes

Replace the transformer.

— 11 —

No

Replace the power switch.

No

Set the voltage selector at
proper position.

2. No sound

Does the power indicator

light up?

Yes

Check the main volume.

Is it OK?

Yes

Disconnect CA
connectors on the main PCB.

Press Demo button.

Does the demo tune sound?

No

Follow "No power"
troubleshooting.

No

Replace main volume.

No

3. Distorted sound

Yes

Replace keyboard PCBs.

Replace PS2M PCB.

Is a sound ok?

No

Replace MA1M PCB.

Replace the main PCB.

Yes

End

— 12 —

4. Certain keys do not function

Replace MA1M PCB.

Do the keys function?

Replace keyboard PCBs.

5. A certain key does not function

Clean the contact.

Does the key function?

Replace the key contact rubber.

Does the key function?

Yes

No

End

Yes

No

Yes

No

Replace keyboard PCBs.

6. A certain button does not function

Replace CN1M PCB.

Does the button function?

No

Replace MA1M PCB.

End

Yes

End

— 13 —

WIRING DIAGRAM

POWER LAMP SPEAKERS

CH1
CH2

LVD

DG

PHONES

CH1

JCM425-PS3M

CH2

CG1

CG2

CG3

CG4

CG5

CG6

CG7

JCM425-PS4M

AG

DG

LVD

LSP

LHP

RSP

RHP

JCM425-CN1M

RmelI

LmelI

(

RED

AG
Lmel0
Rmel0

CF1

)

CF2

)

CF3

)

CF4

)

CF5

)

(

BROWN

(

BLACK

(

ORANGE

(

YELLOW

JJ1

JJ2

JCM431-PS12

L
N

TRANSFORMER

LSP–

LSP+

RSP+

RSP–

CG1

CG2

CG3

CG4

CG5

CG6

CG7

S1
S2
S3
S4

C

JCM425-PS2M

CC1

CC2

CC3

CC4

CC5

CC6

CC7

CC8

CC9

CC10

CC11

CC12

CL1

CL2

CR1

CR2

CF1
CF2
CF3
CF4
CF5

POWER SWITCH

Rmei1

Rmel2

CC1

CC2

Lmel1

Lmel2

CC3

CC4

AG

CC5

AVDD

CC6

VDD

CC7

DG

CC8

Min

MUTE

CC9

CC10

FG

Mout

CC11

CC12

VDDB

BRILLIANCE

JJ1

JJ2

LEFT

RIGHT

JJ3

JJ4

JJ5

KI0

KC4

AGB

JJ3

JJ4

JJ5

SOFT

VDDB

DAMPER

SOSTENUTO

CE-1

CE-2

CE-3

CE-4

PEDAL

UNIT

DG

VDD

NRES

NRD

NWR

CE

A2

A1

A0

DB3
DB2
DB1
DB0

VDDB

CD-1
CD-2
CD-3
CD-4
CD-5

–

CD-6
CD-7
CD-8
CD-9
CD-10
CD-11
CD-12
CD-13
CD-14
CD-15

CE-1
CE-2
CE-3
CE-4

JCM425-MA1M

CA1

CA2

CA3

CA4

CA5

CA6

CA7

CA8

CA9

CA10

CA11

CA12

CA13

CA14

CA15

CA16

CA17

CA18

CA19

CA20

CA21

CA22

CA23

CA24

CA25

CA26

CA27

CA28

CD-1
CD-2
CD-3
CD-4
CD-5
CD-6
CD-7
CD-8
CD-9
CD-10
CD-11
CD-12
CD-13
CD-14
CD-15

CA29

BRILLIANCE

CA30

JCM425-CN1M

FI9

FI8

FI7

FI6

FI10

CA1

SI10

CA2

CA3

SI9

CA4

CA5

SI8

CA6

CA7

SI7

CA8

CA9

SI6

CA10

FI5

CA11

SI5

CA12

KC7

CA13

KC6

CA14

KC5

CA15

KC4

CA16

KC3

CA17

KC2

KC1

CA18

CA19

KC0

CA20

SI4

CA21

FI4

CA22

CA23

SI3

FI3

CA24

SI2

CA25

FI2

CA26

SI1

CA27

FI1

CA28

SI0

CA29

FI1

CA30

JCM887T-KY1M JCM887T-KY2M JCM887T-KY3M

JX-1

JX-2

JX-3

JX-4

JX-5

JX-6

JX-7

JX-8

JX-9

JX-10

JX-11

JX-12

JX-13

JX-14

JX-15

JX-16

JX-16

JX-15

JX-14

JX-13

JX-12

JX-11

JX-10

JX-9

JX-8

JX-7

JX-6

JX-5

JX-4

JX-3

JX-2

JX-1

JY-1

JY-2

JY-3

JY-4

JY-5

JY-6

JY-7

JY-8

JY-9

JY-10

JY-11

JY-12

JY-13

JY-14

JY-15

JY-16

JY-16

JY-15

JY-14

JY-13

JY-12

JY-11

JY-10

JY-9

JY-8

JY-7

JY-6

FI0
SI0
FI1
SI1
FI2
SI2
FI3

SI3
KC0
KC1
KC2
KC3
KC4
KC5
KC6
KC7

FI10
SI10

FI9
SI9
FI8
SI8
FI7

SI7
KC7
KC6
KC5
KC4
KC3
KC2
KC1
KC0

JY-5

JY-4

JY-3

JY-2

JY-1

— 14 —

1

11

11

10

12

14

15

16

17

18

19

30

31

32

33

34

20

21

22

23

24

25

26

27

28

29

2

3

4

5

6

R-1

R-2

R-5

R-7

R-8

R-9

R-10

R-11

R-6

R-3

R-4

13

9

8

7

× 2

× 1

× 4

× 4

× 8

× 2

× 2

× 4

EXPLODED VIEW

— 15 —

PARTS LIST

AP-21

Notes: This parts list does not include the cosmetic parts, which

parts are marked with item No. "R-X" in the exploded
view.
Contact our spare parts department if you need these
parts for refurbish.

1. Prices and specifications are subject to change with­out prior notice.

2. As for spare parts order and supply, refer to the
"GUIDEBOOK for Spare parts Supply", published
seperately.

3. The numbers in item column correspond to the same
numbers in drawing.

— 16 —

PARTS PRICE LIST
AP-21

N Item Code No. Part Name Specification Q Price Code R Remarks

BT1

D1 - D4

D5
D6

IC1

N

N

N

IC2
IC3
IC5

LSI1

LSI10

LSI2

LSI3, LSI8 - LSI9

LSI4 - LSI5

LSI6
LSI7 2012 1316 LSI HG51B155FD-1 1 BU

Q1 - Q2

Q3
Q4 2252 0637 TRANSISTOR 2SC4081T106R 1 AA

SNF1

X1
X2

1

D301 - D318

LED301 - LED317

LSI301

SW301 - SW318

VR301
VR302

2

D401 - D404, D415 2390 2996 DIODE 1SR139-400T-32 5 AA B

D405 - D408 2390 3022 DIODE 3BZ41(LC6-15) 4 AD B
D409 - D414
D417 - D421

D416 2390 1323 DIODE RB100A-T32-T 1 AC B

D422 - D423 2360 1729 DIODE / ZENER MTZJ5.1AT-77-T 2 AA B

F402 3632 0719 FUSE / UL TIME-LAG UL-TSC-1A-N1 1 AF A For 110 - 127V area

F402 3631 1037 FUSE / TIME-LAG (S)T-1A 1 AE A For 220 - 240V area
F403 - F404 3632 0301 FUSE / UL TIME-LAG UL-TSC-4A-N1 2 AF A For 110 - 127V area
F403 - F404 3632 0049 FUSE / TIME-LAG (S)T-4A 2 AF A For 220 - 240V area

IC401
IC402
IC403
IC404

IC405
IC406, IC408
IC410, IC411

IC409 2114 1421 IC / PHOTO COUPLER PC900V 1 AK B

J401 - J402 3612 0584 JACK YKB21-5012 2 AD A
J403 - J404 3612 0789 JACK YKB21-5010 2 AC A

J405 3501 4816 JACK / DIN YKF51-5051 1 AH B

Q401 - Q404 2254 0551 FET 2SK365-BL(TPE4) 4 AC A

3 6927 5520 PCB ASSY / M425-PS2M M241035*2 DN A For 110 - 127V area
3

Main PCB

3815 0794 BATTERY / LITHIUM CR2032/1VC1 1 AI B
2390 2576 DIODE / SCHOTTKY RB501V-40TE-17 4 AB B
2390 2576 DIODE / SCHOTTKY RB501V-40TE-17 1 AB B
2360 3057 DIODE / ZENER UDZTE-173.3B 1 AA B
2105 1120 IC / L-MOS TC7S08F(TE85R) 1 AB B
2105 6657
2011 8806 IC / C-MOS TC74HC04AF(TP1) 1 AC B
2114 4060 IC / MONOLITHIC MB3771PF-EF 1 AK B
2011 5222 LSI HD6435328RC13F 1 CB A
2011 5194 LSI HG52E35P 1 BJ A
2012 6404 LSI LH532KU3 1 AT A
2012 5572 LSI TC55257DFL-70L(EL) 3 AS A
2114 4221 LSI UPD6376GS-E1 2 AS A
2012 5707 LSI MX23C2410MC-12CA58 1 BO A

2250 1162 TRANSISTOR 2SA1576AT106R 2 AA B
2250 1162 TRANSISTOR 2SA1576AT106R 1 AA B

3025 1505 FILTER / EMI NFM51R00P106 1 AC B

2590 2100 OSCILLATOR CSACS20.00MX040-TC 1 AG B
2590 1043 OSCILATOR AT-49-16.384M 1 AK B
6927 5470 PCB ASSY / M425-MA1M M241032*1 1 EM A

Console PCB

2390 1344 DIODE 1SS133T-77 18 AA B
2370 1416 LED SLZ-190B-03-T2 17 AA B
2011 0812 LSI UPD65005GF-419 1 AT A
3412 0903 SWITCH / TACT EVQ-21405R 18 AA A
2765 0280 VOLUME EWA-NAXCH1B14 1 AI A
2765 2187 VOLUME EWA-NFECH1B54 1 AG A
6927 5560 PCB ASSY / M425-CN1,2M M241033*1 1 DD A

Power supply PCB

2390 1344 DIODE 1SS133T-77 11 AA B

2114 5794
2114 5795
2114 5797
2114 5796
2114 1106 IC / HYBRID STK4132MK2 1 BL B
2114 1799 IC / MONOLITHIC M5218APR 4 AC B

6927 5530 PCB ASSY / M425-PS2M M241035*3 DN A

IC / C-MOS

IC / MONOLITHIC
IC / MONOLITHIC
IC / MONOLITHIC
IC / MONOLITHIC

TC74HC10AF(TP1) 1 AB B

NJM78M15FA 1 AE B
NJM79M15FA 1 AG B
NJM78L05A(T3) 1 AE B
NJM78M05FA 1 AE B

A

B

For 220 - 240V area

- 17 -

N Item Code No. Part Name Specification Q Price Code R Remarks

F401 3632 0294 FUSE / UL TIME-LAG MT4-2A-N1 1 AF A For 110 - 127V area
F401 3631 1037 FUSE / TIME-LAG (S)T-1A 1 AE A For 220 - 240V area

J406 - J407 3502 2657 JACK / PHONE YKB22-5006 2 AF A

N

N

N
N
N
N

N
N

N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N

N

N
N

L401 3013 2577 COIL / CHOKE PLAC1522R0R01B1 1 AM C

LED401 2370 1417 LED SLP-135B-51 1 AA B

4 6927 5490
4
5 6927 5540 PCB ASSY / M425-PS3M M341013*1 1 CO B
6 6927 5580 PCB ASSY / M425-PS4M M341014*1 1 BJ B

D701 - D876 2390 3043 DIODE 1S2076TE 176 AA B

7 6927 3270 PCB ASSY / M887T-KY1M M240951*1 1 BO C
8 6927 3280 PCB ASSY / M887T-KY2M M240952*1 1 BT C
9

10 3012 1614 TRANSFORMER TE-425-1M1 1 CA B For 110 - 127V area
10 3012 1615 TRANSFORMER TE-425-2M1 1 CA B For 220 - 240V area
11 3831 1077 SPEAKER SG16G51BFA 2 BS B
12

13 6927 3230 KY ASSY M140830*1 1 EO B
14 6927 3980 RUBBER / CONTACT AB M240957-1 1 AE A
15 6927 3990 RUBBER / CONTACT CB M240958-1 6 AH A
16 6927 4000 RUBBER / CONTACT CS M240959-1 1 AH A
17 6927 3250 HAMMER ASSY / WHITE KEY M340962*1 52 BF B
18 6927 3260 HAMMER ASSY / BLACK KEY M340963*1 36 BF B
19 6927 4030 BLACK KEY M140784-1 36 AG A
20 6927 4040 WHITE KEY / C M140783-1 7 AH A
21 6927 4050 WHITE KEY / D M140785-1 7 AI A
22 6927 4060 WHITE KEY / E M140786-1 7 AH A
23 6927 4070 WHITE KEY / F M140787-1 7 AI A
24 6927 4080 WHITE KEY / G M140788-1 7 AH A
25 6927 4090 WHITE KEY / A. M140789-1 7 AH A
26 6927 4100 WHITE KEY / B M140790-1 8 AI A
27 6927 4110 WHITE KEY / SA M140792-1 1 AM A
28 6927 4120 WHITE KEY / SC M140791-1

29 6924 5260 BUTTON / POWER M340318-1 1 AA B
30 6919 3241 KNOB /SLIDE M311405-1 2 AB B
31 6927 5730 SWITCH ASSY / POWER M341019*1 1 BN B

32 6927 5680 PEDAL-BOX M241018*1 1 CX B
33 1004 3475 SCREW SET -415MM M341366C-1 1 BL B

34 3701 1142 AC cord 5-989660 1 AZ C 120V, USA
34 3701 0595 AC cord EC-654-E06 1 BP C 230V, Europe

PS12,PS3,PS4M PCB's

PCB ASSY / M425-PS12

6927 5500 PCB ASSY / M425-PS12 M341012*3 1 BR B

Keyboard PCB's

6927 5610

Other electrical parts

3613 0217 RECEPTACLE NC-174-10-C 1 AJ C

Keyboard unit

Mecanical parts

Stand

AC cord

PCB ASSY / M887T-KY3M M241019*1

M341012*2 1 BS B For 110 - 127V area

1 BM C

1 AN A

For 220 - 240V area

240V, Other countries

34 3701 1008 AC cord SP22-17022A 1 CD C 230V, UK

Notes: N- New parts

Q-Quantity used per unit
R-Rank

- 18 -

MAIN PCB JCM425-MA1M

SCHEMATIC DIAGRAMS

3

4

5

— 19 —

MAIN (B) & POWER SUPPLY PCBs JCM425-PS12/PS2M/PS3M/PS4M (AC : 220 - 240V AREA)

— 20 —

1

2

MAIN (B) & POWER SUPPLY PCBs JCM425-PS12/PS2M/PS3M/PS4M (AC: 110 - 127V AREA)

— 21 —

1

2

CONSOLE PCB JCM425-CN1M, CN2M

1

2

8

7

6

— 22 —

KEYBOARD PCB JCM887T-KT1M

— 23 —

KEYBOARD PCB JCM887T-KT2M

— 24 —

KEYBOARD PCB JCM887T-KT3M

— 25 —

Ver. 1 : Correction of page 18.

CASIO TECHNO CO.,LTD.

Overseas Service Division

Nishi-Shinjuku Kimuraya Bldg. 1F
5-25, Nishi-Shinjuku 7-Chome
Shinjuku-ku, Tokyo 160-0023, Japan