ELECTRONIC KEYBOARD

AP-20

(with price)

— 2 —

CONTENTS

Safety Notice ...................................................................................... 2

Specifications .................................................................................... 3

Block Diagram ................................................................................... 4

PCB Layout ........................................................................................ 5

Disassembly Instructions ................................................................. 6

Circuit Description .......................................................................... 10

Major Waveforms ............................................................................. 12

Troubleshooting .............................................................................. 13

Wiring Diagram ................................................................................ 17

Exploded View ................................................................................. 18

Parts List .......................................................................................... 21

Schematic Diagrams ....................................................................... 23

SAFETY NOTICE

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

— 3 —

SPECIFICATIONS

GENERALNumber of keys 88

Polyphonic: 32-note

Preset tones: 10, PIANO 1, PIANO 2, ELEC. PIANO, HARPSICHORD, VIBRAPHONE,PIPE ORGAN, STRINGS, CHOIR, W.BASS (Lower tone only),E.BASS (Lower tone only)

Layer/Split function

Key transpose: F#-C-F

Keyboard controls: Tuning curve, Baroque pitch

Temperaments: Equal Temperament, Kirnberger III, Werckmeister, Mean-Tone,Just Intonation (Minor/Major), Pythagorean System

Effects: Reverb (Room, Stage, Hall 1, Hall 2)/Chorus/Tremolo/Brilliance

Demo tunes: 8, 1. Polonaise "Héroïque" (F.F. Chopin)2. Frühlingslied Op. 62-6 (F. Mendelssohn)3. CASIO original4. Harmonious blacksmith (G.F. Händel)5. CASIO original6. Jesus, Bleibet Meine Freude (J.S. Bach)7. CASIO original8. CASIO original

Memory: Number of Songs: 2 (A and B)System: Real-time recordingMemory Capacity: Approximately 3,000 notes totalMemory Backup Battery: Built-in lithium battery

Battery Life: Approximately 5 years

Pedals: Soft, Sostenuto, Damper

Tuning control: 440Hz ±50 centsBuilt-In Speakers: 16 cm dia. x 2 (Output: approx. 20 W + 20 W)

MIDI: 16-channel, multi-timbral reception

Terminals: PHONES 1 and 2, MIDI (IN/OUT/THRU), LINE OUT L and R (Output Imped-ance: 10 KΩ; Output Voltage: 2 V, RMS, max.), LINE IN R and L (Input Imped-ance: 20 KΩ, Input sensitivity: 200 mV)

Power source: 120V (for U.S.A.),120V, 220V, 230V and 240V (for other countries)

Power consumption: 65W (with 120V AC), 55W (with 220V, 230V and 240V AC)

Dimensions (HWD): Without stand: 185 × 1340 × 520 mm (7-5/16 × 52-13/16 × 20-1/2 inches)With stand: 820 × 1360 × 550 mm (32-5/16 × 53-9/16 × 21-11/16 inches)

Weight: Without stand: 35.5 kg (78.3 lbs)/38.5 kg (84.0 lbs)With stand: 45.5 kg (100.4 lbs)/48.5 kg (106.1 lbs)

Note: There are two models of AP-20, one has a keyboard cover, the other has no keyboard cover.

— 4 —

DSPHG51B155FD

RAM256K

HM62256BLP-10

ROM1M

MX23C1010PC- 12CA25

CPUHD6435328RC13F

PEDAL

MIDIIN OUT

ROM8M + 16M

HN62418PD25HN624116D44

RAM256K × 2

HM65256BLSP- 10 × 2

Keyboard

ControllerHG52E35P

Switch & LEDController

µPD65005GF-419

D/A ConverterµPD6376CX

D/A ConverterµPD6376CX

Filter

Mixer, Mute CircuitT6, T7, T10, T11

Power Amp.STK4132MK

RA0 ~ 19

RD0 ~ 15

EA0 ~ 14

ED0 ~ 15

A0 ~ 3

A0 ~ 14

D0 ~ 7

KC0 ~ 4

KI0 ~ 3

L1 ~ 9LA ~ J LEDs

Switches

KeyboardKC0 ~ 7

FI0 ~ 10SI0 ~ 10

MainVolume

Vol

tage

Reg

ulat

orM

5F78

M12

L ×

2M

527B

L05

T8,

T9

AVC

CAV

DD

AVFF

VDD

+12V

+5V

–12V

+5V

SOLM, SOLP BDK, WOK1, SORM, SORP

Pow

er S

witc

h

Pow

er T

rans

form

er

T10

1

Reset ICMB3771P

RST

MUTE

BRILLIANCE

MIDI MIDOSFSSDP

Filter

LINE IN

P70 ~ P77

P12 ~ P14

BLOCK DIAGRAM

— 5 —

POWER

VOLUME

MIN MAX

HALL 2BRILLIANCE

MELLOW BRIGHT

CONTROL

PIANO 1

TONE

PIANO 2 E.PIANO HARPSICHORD PIPE ORGAN STRINGS CHOIRVIBRAPHONE W.BASS E.BASS

LOWER TONE REVERB

HALL 1

STAGE

ROOM

TREMOLO

CHORUSSONG A

MEMORY

SONG B RECORDSTART/STOP

TUNE DEMO

OFFON

MA2M

MA1MPS1

CN2M CN1M CN3M

IF1M

MA4M MA5M

TP10-KY1M TP10-KY2M

PCB LAYOUT

Note: IF1M PCB is a terminal board for the keyboard PCBs, and included in the main PCB.

PCB

Main PCB

Jack PCBs

Console PCBs

Power PCB

JCM433-

MA1M

MA2M

MA4M

MA5M

CN1M

CN2M

CN3M

PS1

Components

CPU, DSP, Sound Source ROM Working storageRAM, Effect RAM Reset IC, DAC, Filter, Key con-troller, Power amp, Power supply circuit

LINE IN/OUT jack, MIDI jacks

Phone jacks

Power indicator

Gate array (Button controller/LED driver), LEDs,Buttons

Main Volume, Brilliance volume

Tune Buttons, Demo button

Fuse, Noise filter

— 6 —

DISASSEMBLY INSTRUCTIONS

1. Disassembling top board

1-1. Remove 8 screws on the rear.

1-2. Slide the top board towards the rear.

The top board will be free from catches on the

case.

1-3. Lift the top board.

For keyboard-cover model2. Disassembling keyboard cover

2-1. Slide the keyboard cover to open fully.

2-2. Passing the gear into the opening on each

rack, lift the keyboard cover.

For no-keyboard-cover model2. Disassembling the front cover

2-1. Remove 4 screws at both ends of the front cover.

2-2. Remove the front cover.

— 7 —

3. Disassembling console panel

Note: To avoid scratch on the side board, put paper between the

console panel and the side board at both ends.

3-1. The console panel is fixed with screws and nuts. Holding the

nut, remove the screw.

3-2. Remove the screw fixing a grounding wire at the transformer.

3-3. Slide the console panel towards the front to free from catches.

3-4. Turn round the console panel.

3-5. Remove the 2 screws fixing the power switch.

Insert paper here.Insert paper here.

4. Disassembling front cover

4-1. Remove 5 screws at the front edge on the bottom.

4-2. Disconnect the connector for phone jacks from the main PCB.

4-3. Watching the phone-jack cable, pull out the front cover towards the front.

— 8 —

5. Disassembling keyboard unit

5-1. Remove 6 screws at both ends on the bottom, and a screw at the middle.

5-2. Remove 2 screws at both ends of keyboard unit.

5-3. Disconnect 2 connectors for the keyboard unit from the main PCB.

5-4. Moving the keyboard unit towards the front, remove the unit from the case.

6. Disassembling keys

6-1. Peel the red felt and sponges off the keyboard unit.

6-2. Using a long-nose plier, remove key springs.

6-3. Pressing the hook with a long-nose plier. Lift the key.

— 9 —

7. Disassembling keyboard PCBs

7-1. Turn round the keyboard unit to face the PCB

up.

7-2. Disconnect the connector at the middle of

keyboard.

7-3. Remove screws on the keyboard PCBs.

Jumper

8. Replacing the main PCB

Note: The main PCB contains a lithium battery for memory back-up. Please remove the jumper

before replacing the PCB. And make sure that the jumper is reset on new main PCB after

replacing the PCB. Because no jumper is set on a spare part of the main PCB.

— 10 —

CIRCUIT DESCRIPTION

KEYMATRIX

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

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

FI

KC

SI

LSIUPD912GF-3BA

Second contact First contact

— 11 —

KI0 KI1 KI2 KI3

KO0 Piano2 E. Piano Harpsichord W. Bass

KO1 Piano1 Strings Choir E. Bass

KO2 Vibraphone Pipe organ Reverb

KO3 Song A Song B Record Start/Stop

KO4 Control Tune up Tune down Demo

BUTTON MATRIX

POWER SUPPLY CIRCUITThe power supply circuit generates four voltages as shown in the following table.

Name Voltage For operation of

VDD +5 V CPU, Reset IC, Working storage RAM, DSP, Key touch LSI, Sound

source ROM, Effect RAM, Gate array

AVDD +5 V DAC

AVCC +12 V Filter, Mixer

AVFF -12 V Filter, Mixer

— 12 —

MAJOR WAVEFORMS

CH1 .2V CH2 .2V˜ ˜

A 1ms

CH1

CH2

1

2

1 Filter output L-ch CC connector pin 12 Filter output R-ch CC connector pin 2

6 Button scan signal KC0 UPD65005GF-419 pin 537 Button scan signal KC1 UPD65005GF-419 pin 548 Button scan signal KC2 UPD65005GF-419 pin 55

CH1 5V CH2 5V

A 2ms

CH1

CH2

6

7

CH2 5V

CH38

Tone : Piano 1Key : A4

3 Key scan signal KC0 JA connector pin 54 Key scan signal KC1 JA connector pin 45 Key scan signal KC2 JA connector pin 3

CH1 5V CH2 5V˜ CH3 5V

A 20 µs

CH1

CH2

3

5

4

CH3

— 13 —

Check fuse F101.

Is F101 blown up?

Check fuses F2, F3, and F4.

Are the fuses blown up?

Are the voltages 40 V ACand 8 V AC?

Is it OK?

Is it OK?

Measure output voltages of the transformer.

Replace the transformer.

No

No

Replace F101.

Replace F2, F3, and F4.

Yes

Yes

No

No

Yes

Yes

Yes

Replace main PCB. No

Replace the power switch.

Set the voltage selector at proper position.

Check position of voltage selector.

Check the power switch.

TROUBLESHOOTING

1. No power

— 14 —

Does the power indicator light up?

Check the main volume.

Is it OK?

Does the demo tune sound?

Replace keyboard PCBs.

Disconnect JA and JB connectors on the main PCB.

Follow "No power" troubleshooting.

No

Yes

Yes

Yes

No

No

Replace main volume.

Press Demo button.

Replace the main PCB.

2. No sound

3. Distorted sound

Check the voltage selector.

Is it at proper position?No

Yes

Replace the main PCB.

Set the voltage selector at proper position.

— 15 —

4. Certain keys do not function

5. A certain key does not function

Clean the contact.

Does the key function?

Does the key function?

Yes

No

No

Replace the key contact rubber.

Replace keyboard PCBs.

End

Yes

Does the key function?

Replace the main PCB.

Yes

No

Replace the main PCB.

Do the keys function?Yes

No

Replace keyboard PCBs. End

— 16 —

Replace the console PCBs.

Does the button function?Yes

No

Replace MA1M PCB. End

6. A certain button does not function

— 17 —

JCM433-MA1M

KC4KC3KC2KC1KC0SI4FI4SI3FI3SI2FI2SI1FI1SI0FI0

SI10FI10SI9FI9SI8FI8SI7FI7SI6FI6SI5FI5KC7KC6KC5

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

SI0KC0FI0KC1SI1KC2FI1KC3SI2KC4FI2KC5SI3KC6FI3KC7SI4NCFI4NC

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

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

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

CA-1CA-2CA-3CA-4CA-5CA-6CA-7CA-8CA-9CA-10CA-11CA-12CA-13CA-14CA-15CA-16CA-17CA-18CA-19CA-20

CA-1CA-2CA-3CA-4CA-5CA-6CA-7CA-8CA-9CA-10CA-11CA-12CA-13CA-14CA-15CA-16CA-17CA-18CA-19CA-20

SI5KC0FI5KC1SI6KC2FI6KC3SI7KC4FI7KC5SI8KC6FI8KC7SI9FI10FI9

SI10

CB-1CB-2CB-3CB-4CB-5CB-6CB-7CB-8CB-9CB-10CB-11CB-12CB-13CB-14CB-15CB-16CB-17CB-18CB-19CB-20

CB-1CB-2CB-3CB-4CB-5CB-6CB-7CB-8CB-9CB-10CB-11CB-12CB-13CB-14CB-15CB-16CB-17CB-18CB-19CB-20

AGBBRILLIANCEAVDDB

DB0DB1DB2DB3A0A1A2CE

NRDNWRNRES

CF-1CF-2CF-3CF-4CF-5CF-6CF-7CF-8CF-9CF-10CF-11CF-12CF-13CF-14CF-15CF-16

CF-1CF-2CF-3CF-4CF-5CF-6CF-7CF-8CF-9CF-10CF-11CF-12CF-13CF-14CF-15CF-16

TVOLTVOR

AGTVRLTVRR

CE-BRCE-RCE-ECE-OCE-Y

CE-1CE-2CE-3CE-4CE-5

GYBKPPBROGR

CU-1CU-2CU-3CU-4CU-5GR

CR-1CR-2CR-3

CS-1CS-2CS-3

+–

NC

+–

NC

JCM433-MA2M

JCM433-MA4M

Power Transformer

JCM433-PS1

JCM433-IF1M TP8/10 KY1

JCM433-CN3M

TP8/10 KY2

Pedal Unit

JCM433-CN1M

JCM433-CN2M

Y BL W R

CV

-1C

V-2

CV

-3C

V-4

CV

-1C

V-2

CV

-3C

V-4

Voltage Selector

KI0

KC

4AV

DDB

BRILL

IANCE

AG

B

JX-1

JX-2

JX-3

JX-4

JX-5

JX-1

JX-2

JX-3

JX-4

JX-5

SF

SS

DP

AV

DD

P

SOFT

SOST

EDA

MP

COMM

ON

CD

-1C

D-2

CD

-3C

D-4

CT

-1C

T-2

CT

-3C

T-4

CT

-5C

T-6

CT

-7C

T-8

CT

-9

KC

7N

CF

I4S

I4

1 2 3 4

1 2 3 4

CT

-1C

T-2

CT

-3C

T-4

CT

-5C

T-6

CT

-7C

T-8

CT

-9

PHONES

KC

4K

I3K

I2K

I1

JY-1

JY-2

JY-3

JY-4

JY-1

JY-2

JY-3

JY-4

MID

0M

ID1

VD

DD

GA

GF

GA

GA

VF

FA

VC

CLI

RA

GLI

LLO

RA

GLO

L

CC-1

CC-2

CC-3

CC-4

CC-5

CC-6

CC-7

CC-8

CC-9

CC-1

0CC

-11

CC-1

2CC

-13

CC-1

4CC

-15

CC-1

CC-2

CC-3

CC-4

CC-5

CC-6

CC-7

CC-8

CC-9

CC-1

0CC

-11

CC-1

2CC

-13

CC-1

4CC

-15

R L R L IN OUT THRULINE IN LINE OUT MIDI

NC

BK

C-1

C-2

WIRING DIAGRAM

— 18 —

EXPLODED VIEW

STAND

x12

x4

x4x4x1

x2x4x4

R-8 R-9

R-10

R-11R-12 W

X

— 19 —

30

12

3

4

5

6

7

8

9

R-2R-5

R-3

R-6

R-4

R-7

R-1

10

11 13

1415

16

1217

18

17

18

19

2021

25

24

26

26

27

29

31

22

23

28

32

Notes: This parts list does not include the cosmetic parts, whichparts are marked with item No. "R-X" in the explodedview.Contact our spare parts department if you need theseparts for refurbish.

1. Prices and specifications are subject to change with-out prior notice.

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

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

PARTS LIST

AP-20

FOB JapanN Item Code No. Parts Name Specification Q N.R.Yen R

Unit PriceMain PCB

2200 4409 Transistor 2SA933-SQ-TP-T 3 8 B2220 1387 Transistor 2SC1740SQ-TP-T 2 8 B2240 1050 FET 2SK163N-T 4 31 B2360 0273 Zener diode RD3.3ESB1-T1-T 1 8 B2360 1694 Zener diode RD6.2ESB1-T1-T 1 8 A2011 0455 LSI, RAM HM65256BLSP-10 2 450 A2011 3325 LSI, DAC UPD6376CX 2 190 A2011 5194 LSI, Key controller HG52E35P 1 540 A2011 5208 LSI, ROM, Sound source HN624116PD44 1 1,260 A2011 5222 LSI, CPU HD6435328RC13F 1 1,260 A2011 5236 LSI, ROM, Sound source HN62418PD25 1 870 A2011 7434 LSI, DSP HG51B155FD 1 1,160 A

N 2012 0560 LSI, RAM HM62256BLP-10.8 1 600 A2012 2093 LSI, ROM MX23C1010PC-12CA25 1 290 A2101 0731 IC, NADD gate TC74HC10AP 1 32 B2105 1092 IC, NOT gate TC74HC04AP 1 30 B2114 0021 IC, OP-amp. LA6462D 5 39 B2114 0140 IC, Reset MB3771P 1 90 B2114 0854 IC, Regulator M5278L05 1 78 A2114 1106 IC, Hybrid, Power amp. STK4132MK2 1 650 A2114 1113 IC, Regulator M5F78M12L 1 91 A2114 2163 IC, Regulator M5F79M12L 1 78 A2230 5229 Transistor 2SD1666R,S 1 60 A2390 2366 Diode stack S4VB20-4033(L10) 1 190 B2529 2034 Ceramic oscillator CSA20.00MX040 1 52 B2590 1519 Crystal oscillator HC-49U16384 1 100 B3815 0707 Lithium battery CR2032-1HM 1 96 B3631 1070 Fuse, Time-lag (S)T-3.15A 1 39 A3631 1045 Fuse, Time-lag (S)T-1.6A 1 62 A3632 0231 Fuse, Time-lag UL-TSC-3.15A-N1 1 61 A3632 0273 Fuse, Time-lag UL-TSC-1.6A-N1 1 61 A

N 1 6924 7790 Main PCB ass'y M433-MA1M M140334*2 1 14,470 ASub PCB

2105 1092 IC, NOT gate TC74HC04AP 1 30 B2114 0021 IC, OP-amp. LA6462D 1 39 B2114 1421 IC, Photocoupler PC900V 1 100 B3501 4802 DIN jack YKF51-5052 1 120 B3612 0789 Jack, Line IN/OUT YKB21-5010 4 35 A

N 2 6924 4670 Sub PCB ass'y M433-MA2M M240332*1 1 2,170 AConsole PCB

2370 0630 LED LN282RPX-(TX3) 19 21 B3412 0903 Tact switch EVQ-21405R 20 14 A2011 0812 LSI, Gate array, LED driver UPD65005GF-419 1 220 B2765 0280 Slide volume EWA-NAXCH1B14 1 100 A2765 1288 Slide volume EWA-NAXCH1B54 1 100 A

N 3 6924 4760 Console PCB ass'y M433CN-123M M140336*1 1 2,150 AJack PCB

2320 9748 LED LN28RPH 1 20 BN 3613 1533 Jack, Phone HLJ4336-01-3040 1 170 A

4 6924 4690 M433MA4,5M-PCBASSY M240334*1 1 900 BPower PCB

3632 0287 Fuse, Time-lag (S)T-0.63A 1 49 AN 3632 0280 Fuse, Time-lag MT4-1.6A-N1 1 64 AN 5 6924 7810 Power PCB M433-PS1 M240333*2 1 890 C

Notes: N – New partsR – Rank

— 21 —

FOB JapanN Item Code No. Parts Name Specification Q N.R.Yen R

Unit PriceOther electrical parts

6 3012 0567 Transformer TE-351-1M1 1 2,040 B7 3613 0217 Receptacle NC-174-10-C 1 110 B

N 8 3412 1827 Power switch SDDLD1-A2-D 1 130 AKeyboard unit

N 9 6924 1820 Keyboard unit 88TP/10CASIO 1 13,340 BN 10 - 16 6924 9150 White key set, 1-octave 88TP10(42120120) 7 540 AN 19 6924 9150 Black key, 1-octave 88TP10(42120030) 7 540 AN 20 6924 9160 Spring, for white key 88TP10(23100820) 52 15 BN 21 6924 9170 Spring, for black key 88TP10(23100810) 36 15 BN 22 6924 9190 Contact, rubber, for key, 12 88TP10/8(2564230) 6 150 AN 23 6924 9200 Contact, rubber, for key, 13 88TP10/8(2564240) 1 160 AN 24 6924 9060 Keyboard PCB (DX) 88TP10/8(42912070) 1 2,800 CN 25 6924 9070 Keyboard PCB (SX) 88TP10/8(42912080) 1 3,500 C

Mechnical parts26 3831 0546 Speaker EAS-16PL465A 2 1,250 B27 6906 6141 Felt for keyboard M410324A-4 1 140 B

6919 7410 Sponge for felt M411750-1 8 19 B28 6924 5390 Rack L 1037153000 1 170 B29 6924 5410 Rack R 1037154009 1 170 B30 6919 3241 Slide knob A 353 M311405A-1 2 17 B31 6924 5260 Button, power switch M340318-1 1 13 B

N 32 6924 5600 Button set 433 M240304*1 1 170 BStand

33 6924 7050 Pedal box ass'y A190007400 1 5,120 BN 34 6924 7060 Screw set for AP-20's stand A190007500 1 600 B

AC cord3701 0196 AC cord (120V, USA) UC-964-J01 1 650 B3701 0595 AC cord (230V, Europe) EC-654-E06 1 720 B3701 0588 AC cord (230V, UK) BC-323-J01 1 860 B

N 3701 0553 AC cord (240V, Australia) SC-101-J02 1 660 B

Notes: N – New partsR – Rank

— 22 —

— 23 —

34 5

SCHEMATIC DIAGRAMSMAIN PCB JCM433-MA1M (1/2)

DSP

CPUROM(1M)

RAM(256K)

Reset IC

Key Controller

RAM(256K)

RAM(256K)

ROM (16M)

ROM (8M)

D/A Converter

D/A Converter

— 24 —

1

2

MAIN PCB JCM433-MA1M (2/2), PHONE JACK PCBs JCM433-MA4M, MA5M and POWER PCBs JCM433-PS1

40V AC

40V AC

8V AC

8V AC

Power Circuit

Power Amp.

Filter

— 25 —

7

6

8

CONSOLE PCBs JCM433-CN1M, 2M, 3M, and JACK PCB JCM433-MA2M

Switch & LED Controller

— 26 —

INTERFACE PCB JCM433-IF1M

— 27 —

KEYBOARD PCB TP8/10 KY-1

— 28 —

KEYBOARD PCB TP8/10 KY-2

MA0100661A

䄀倀ⴀ㈀　䌀伀一吀䔀一吀匀匀䄀䘀䔀吀夀 一伀吀䤀䌀䔀匀倀䔀䌀䤀䘀䤀䌀䄀吀䤀伀一匀䈀䰀伀䌀䬀 䐀䤀䄀䜀刀䄀䴀倀䌀䈀 䰀䄀夀伀唀吀䐀䤀匀䄀匀匀䔀䴀䈀䰀夀 䤀一匀吀刀唀䌀吀䤀伀一匀䌀䤀刀䌀唀䤀吀 䐀䔀匀䌀刀䤀倀吀䤀伀一䬀䔀夀䴀䄀吀刀䤀堀䈀唀吀吀伀一 䴀䄀吀刀䤀堀倀伀圀䔀刀 匀唀倀倀䰀夀 䌀䤀刀䌀唀䤀吀

䴀䄀䨀伀刀 圀䄀嘀䔀䘀伀刀䴀匀吀刀伀唀䈀䰀䔀匀䠀伀伀吀䤀一䜀圀䤀刀䤀一䜀 䐀䤀䄀䜀刀䄀䴀䔀堀倀䰀伀䐀䔀䐀 嘀䤀䔀圀倀䄀刀吀匀 䰀䤀匀吀匀䌀䠀䔀䴀䄀吀䤀䌀 䐀䤀䄀䜀刀䄀䴀匀䴀䄀䤀一 倀䌀䈀 䨀䌀䴀㐀㌀㌀ⴀ䴀䄀䴀 ⠀⼀㈀⤀䴀䄀䤀一 倀䌀䈀 䨀䌀䴀㐀㌀㌀ⴀ䴀䄀䴀 ⠀㈀⼀㈀⤀Ⰰ 倀䠀伀一䔀 䨀䄀䌀䬀 倀䌀䈀猀 䨀䌀䴀㐀㌀㌀ⴀ䴀䄀㐀䴀Ⰰ 䴀䄀㔀䴀 愀渀搀 倀伀圀䔀刀 倀䌀䈀猀 䨀䌀䴀㐀㌀㌀ⴀ倀匀䌀伀一匀伀䰀䔀 倀䌀䈀猀 䨀䌀䴀㐀㌀㌀ⴀ䌀一䴀Ⰰ ㈀䴀Ⰰ ㌀䴀Ⰰ 愀渀搀 䨀䄀䌀䬀 倀䌀䈀 䨀䌀䴀㐀㌀㌀ⴀ䴀䄀㈀䴀䤀一吀䔀刀䘀䄀䌀䔀 倀䌀䈀 䨀䌀䴀㐀㌀㌀ⴀ䤀䘀䴀䬀䔀夀䈀伀䄀刀䐀 倀䌀䈀 吀倀㠀⼀　 䬀夀ⴀ䬀䔀夀䈀伀䄀刀䐀 倀䌀䈀 吀倀㠀⼀　 䬀夀ⴀ㈀