Casio Oriental Maestro AT1 User manual

ELECTRIONIC KEYBOARD
AT-1
(without price)

CONTENTS
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Replacing the DSP (HG51B155FD) . . . . . . . . . . . . . . . . . . . . . . . . 2
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Circuit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Major Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
PCB View and Major Check Points . . . . . . . . . . . . . . . . . . . . . . . 14
Schematic Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Exploded View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
IC Lead Identification and Internal Diagram . . . . . . . . . . . . . . . . 19
Parts List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

— 1 —
General
Number of Keys: 61
Polyphonic: 32-note
Preset Tones: 100
Tone Expander: Layer, Split
Keyboard Controls: Touch Response: On/Off
Touch Sensitivity: Light/Middle/Heavy
Key Transpose: Range from F# to F by a semitone increment
Oriental Scale Control: Tune: On/Off, Mode: Cent/ Koma
Tuning Rang: Quarter tone (±99 cents) and koma (±5 komas )
Scale Memories: 4
Auto-Rhythms: 50
Tempo Control: 40 to 255
Auto-Accompaniment: CASIO Chord/Fingered/Full-Range Chord
Controller: Variation, Fill-In, Intro/Ending
Magical Presets: 50; BREAK BEAT 20
FREE SESSION 24
KEY SPLIT 6
Digital Effects: 10; Reverb-1, Reverb-2, Reverb-3, Chorus, Tremolo, Phase Shifter,
Organ SP, Enhancer, Flanger, EQ Loudness
Sound/Control Pads: 4
Pad Variations: 32; Phrases: 10, Drums: 10, Percussion: 10, Controllers: 2
Song Memory: 1; System: Real-time recording
Memory Capacity: Approx. 700 notes
Pitch Bender: Bend Range; 2 semitones/3 semitones
Registration Memories: 6
Registration Items: Tone Number, Rhythm Number, Tempo, Accompaniment Mode,
Accompaniment Volume, Effects, Layer On/Off, Split On/Off,
Chord On/Off, Accompaniment Scale On/Off, Pad Variation,
Assignable Jack, Auto-Accompaniment Controller, MIDI (Channel On/Off,
GM On/Off, Local Control On/Off, Bend Range)
Tuning Control: 440Hz ±50 cents
Terminals: Headphone Jack [Output Impedance: 150 Ω, Output Voltage: 5.2 V(rms)
MAX], Assignable Jack, MIDI Jacks (IN, OUT), AC Adaptor Jack (9 V)
Built-In Speakers: 12 cm dia. 2.5 W Input Rating: 2 pcs.
Power Source: 2-way AC or DC source
AC: AC adaptor AD-5
DC: 6 D size dry batteries
Battery life: Approx. 5 hours by manganese batteries R20P(SUM-1)
Auto Power Off: Approximately 6 minutes after the last operation
Power Consumption: 7.7 W
Dimensions (HWD): 129 x 942 x 367 mm
5-1/16 x 37-1/16 x 14-7/16 inches
Weight: 5.3 kg (11.7 lbs) excluding batteries
Standard Accessory: Music stand, Dust cover
SPECIFICATIONS

— 2 —
Electrical
Current Drain with 9 V DC:
No Sound Output 260 mA ±20%
Maximum Volume 930 mA ±20%
with key C3 pressed in Synth-Bass tone and effect No. E-9
Split: On, Layer: On, Oriental scale: On/Cent
Song memory: Play, Volume; maximum, Touch: maximum
Line Output Level (Vrms with 47 KΩload each cannel):
with key F2 pressed in FSynth-Bass tone 2480 mV ±20%
Phone Output Level (Vrms with 8 Ωload each channel):
with key C3 pressed in FSynth-Bass tone 97 mV ±20%
Speaker Input Level:
with key C3 pressed in FSynth-Bass tone 2240 mV ±20%
Minimum Operating Voltage: 6.3 V
REPLACING THE DSP (HG51B155FD)
Note: To increase productivity ,the DSP HG51B155FD is sticked on the main PCB with a double-side
adhesive tape, then its leads are soldered.
Remove the DSP according to the following procedures.
1. Prepare isopropyl alcohol and a flat IC desoldering machine (Spot Heater HS-600).
2. Apply plenty of the alcohol to the adhesive tape from the reverse side of the main PCB. (Fig.1)
There is a hole on the PCB just under the LSI, and the adhesive tape can be seen through the hole.
3. Leave it more than one minute so that the alcohol weaken adhesive power fully.
4. Using a proper size of nozzle, apply heat to leads of the LSI with the desoldering machine.
5. Grasp the LSI with tweezers, and using gentle force vibrate the tweezers to feel melting solder. (Fig.2)
6. Remove the LSI after meltingsolder at every leads wholly.
Alcohl
Spot Heater HS-600
Fig.2Fig.1
HG51A115A
LSI-S

— 3 —
BLOCK DIAGRAM
KC0 ~
KC7
SI0 ~ SI7
FI0 ~ FI7
Key Touch LSI
LSI106
HG52E35P
Working Strage
RAM (64K-bit)
LSI104
SRM2264LC90,10
7-Seg.
LED
LO0 ~ LO4 LED driver
IC301/302
BA612
LD0 ~ LD7
Buttons
KI1 ~ KI7 VDD
Power Switch
MIDI
IN
OUT
EA0 ~ EA12
ED0 ~ ED7
DSP
LSI105
HG51B155FD
RA0 ~ RA19
RD0 ~ RD15
Sound Source ROM
(16M-bit)
LSI103
TC5316200CP-C106
WCK1 SLOP BCK
D/A Converter
LSI101
UPD6376CX
Filter
IC105
Main
Volume
Power Amplifier
IC102
LA4598
CPU
LSI102
HD6433298A36P
Keyboard
A0 ~ A14
POWER
Power Supply Circuit
IC101, Q1 ~ Q4
VCC AVDD VDD
LVDD DVDD
VC
APO
Effect RAM
(64K-bit)
LSI107
SRM2264LC90,10
D0~D7
Speakers
Output
A0 ~
A12
A0 ~ A3
A0 ~ A2
LEDs
LED driver
Q109 ~ Q116 KO Signal
Generator
IC303/304
TC74HC174P
La ~ Lg, Lp
Reset IC
IC104
RE5VA35AA
RESET
KO
CLK KO0 ~ KO10
LC1 ~ LC4
Filter
IC105

— 4 —
Note: Each key has two contacts, the first conatct 1and second contact 2.
CIRCUIT DESCRIPTION
Key Matrix
Key
Second contact 2 First contact 1 FI
KC
SI
F#3 G#3 A#3 C#4 D#4 F#4 G#4 A#4 C#5 D#5 F#5 G#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#2
F#2D#2
C#2 A#6 G#6F#6D#6
C#6
Nomenclature of Keys
KC0 KC1 KC2 KC3 KC4 KC5 KC6 KC7
FI0 C2 1C#2 1D2 1D#21E2 1F2 1F#2 1G2 1
SI0 C2 2C#2 2D2 2D#22E2 2F2 2F#2 2G2 2
FI1 G#21A2 1A#2 1B2 1C3 1C#31D3 1D#31
SI1 G#2 2A2 2A#2 2B2 2C3 2C#32D3 2D#32
FI2 E3 1F3 1F#3 1G3 1G#31A3 1A#3 1B3 1
SI2 E3 2F3 2F#3 2G3 2G#32A3 2A#3 2B3 2
FI3 C4 1C#4 1D4 1D#41E4 1F4 1F#4 1G4 1
SI3 C4 2C#4 2D4 2D#42E4 2F4 2F#4 2G4 2
FI4 C4 1C#4 1D4 1D#41E4 1F4 1F#4 1G4 1
SI4 C4 2C#4 2D4 2D#42E4 2F4 2F#4 2G4 2
FI5 E5 1F5 1F#5 1G5 1G#51A5 1A#5 1B5 1
SI5 E5 2F5 2F#5 2G5 2G#52A5 2A#5 2B5 2
FI6 C6 1C#6 1D6 1D#61E6 1F6 1F#6 1G6 1
SI6 C6 2C#6 2D6 2D#62E6 2F6 2F#6 2G6 2
FI7 G#61A6 1A#6 1B6 1C7 1
SI7 G#6 2A6 2A#6 2B6 2C7 2

— 5 —
Button Matrix
Reset Circuit
Initial reset
When batteries are set or an AC adapter is connected, the reset IC provides a low pulse to the CPU.
The CPU then initializes its internal circuit and clears the working strage RAM.
Power ON reset
When the power switch is pressed, the CPU receives a low pulse of POWER signal. The CPU provides
APO signal to the power supply circuit, then provides RESET signal to the DSP, the key touch LSI and
the KO signal generators.
VDD Battery set
RESET
CPU
LSI102
HD6433298A36P
Reset IC
IC104
RE5VA35AA
Working Strage RAM
LSI104
SRM2264LC90,10
DSP
LSI105
HG51B155FD
Key Touch LSI
LSI106
HG52E35
DVDD
DVDD
DVDD
VDD
VDD
-RESET
POWER
From power switch
KO Signal Generator
IC303/304
TC74HC174P
-NMI
KI1 KI2 KI3 KI4 KI5 KI6 KI7
KO0 Registration 3 2 1 0
KO1 Control Demo Layer Split
KO2 Tone Rhythm 9 8 7 +
KO3 Accomp 6 5 4 -
KO4 G# down A down A# down B down G down
KO5 ScaleMode ScaleTune B up A# up A up G# up G up
KO6 Intro Start/Stop
KO7 C up C# up D up D# up E up F up F# up
KO8 C down C# down D down D# down E down F down F# down
KO9 Mode Pad B Pad D Pad A Pad C
KO10 Rec
Song
Memory
Touch
Response
Transpose/
Tune
Magical
Preset Digital
Effect
Tempo
Down Tempo Up Synchro/ Ending Variation/ Fill-In Normal/ Fill-In
Scale
Memory 1 Scale Memory 2 Scale
Memory 3 Scale Memory 4

— 6 —
CPU (HD6433298A36P)
The 16-bit CPU contains a 32k-bit ROM, a 1k-bit RAM, seven 8-bit I/O ports, an A/D convertor and serial
interfaces. The CPU accesses to the working strage RAM, the DSP and the key touch LSI. The CPU also
controls buttons, bender input, LEDs and MIDI input/output.
The following table shows the pin functions of the CPU.
Digital Signal Processor (HG51B155FD)
Upon receipt of note numbers and their velocities, the DSP reads sound and velocity data from the sound
source ROM in accordance with the selected tone; the DSP can read rhythm data simultaneously when a
rhythm pattern is selected. Then it provides 16-bit serial signals containing data of the melody, chord,
bass, and percussion to the DAC. The DSP also adds the selected effect to the sound data using a 64k-bit
RAM.
The following table shows the pin functions of the DSP.
Pin No. Terminal In/Out Function
1 P40 Out KO signal data output
2 P41 Out Clock for KO signal data
3 P42 Out APO (Auto Power Off) signal output. ON: High OFF: Low
4 P43 Out Read enable signal output
5 P44 Out Write enable signal output
6 P45 Not used
7 P46 Out 10 MHz clock output
8 P47 In Wait signal input. Connected to +5 V.
9 TXD Out MIDI signal output
10 RXD In MIDI signal input
11 P52 Out Reset signal output
12 -RESET In Reset signal input
13 -NMI In Power ON signal input
14 VCC In +5 V source
15 -STBY In Standby signal input. Connected to +5 V.
16 VSS In Ground (0 V) source
17, 18 XTAL,EXTAL In 20 MHz clock input
19, 20 MD1, MD0 In Mode selection input.(Internal ROM mode --- MD1: High MD0: Low)
21 AVSS In Ground (0 V) source for the built-in DAC
22 AN0 In Analog input. Connected to ground.
23 ~ 29 P71 ~ P77 In Ternimal for button input signal
30 AVCC In +5 V source for the built-in DAC
31 ~ 38 P60 ~ P67 Out LED segment signal output
39 VCC In +5 V source
40 P27 Not used
41 ~ 56 P26 ~ P10 Out Address bus
48 VSS In Ground (0 V) source
57 ~ 64 P30 ~ P37 In/Out Data bus

— 7 —
Pin No. Terminal In/Out Function
1 ~ 8 CD0 ~ CD7 In/Out Data bus
9, 10 Not used
11 GND7 In Ground (0 V) source
12 CK16 Out 16.384 MHz clock output
13 VCC6 In +5 V source
14 CK0 In Clock input. Connected to terminal CK16.
15 TCKB Not used
16 VCC1 In +5 V source
17 GND1 In Ground (0 V) source
18, 19 XT0, XT1 In/Out 16.384 MHz clock input/output. Connected to a crystal oscillator.
20 SGL In System control terminal. Single chip system: Open
21 CCSB In Chip select signal input
22 ~ 25 CA0 ~ CA3 In Address bus
26 CE0 In Not used. Connected to ground.
27 CWRB In Write enable signal
28 CRDB In Read enable signal
29 ~ 32 Not used
33 RESB In Reset signal input
34 TESB In Not used. Connected to +5 V.
35 ~ 39 Not used
40 ~ 49
52 ~ 57
50 VCC2 +5 V source
51 GND2 Ground (0 V) source
58 RA23 Out Not used
59 RA22 Out Chip select signal for the sound source ROM
60, 61 RA20, RA21 Out Not used
62 ~ 73
75 ~ 82
74 GND5 In Ground (0 V) source
83 WOK2 Out Word clock output. Not used.
84 VCC3 In +5 V source
85 GND3 In Ground (0 V) source
86 WOK1 Out Word clock for the DAC
87 SOLM Out Serial data output. Not used.
88 SOLP Out Serial sound data output for the DAC
89 BOK Out Bit clock output for the DAC
90 ~ 92 Not used
93 VCC5 In +5 V source
94 EA14 Out Not used
95, 97
99 ~ 105
107, 109
110, 112
RD0 ~ RD15 In Address bus for the sound source ROM
RA0 ~ RA19 Out Address bus for the sound source ROM
EA0 ~ EA12 Out Address bus for the effect RAM

— 8 —
DAC (UPD6376CX)
UPD6376CX is a two-channel 16-bit Digital to Analog Convertor consisting of resistor string, output
amplifier and zero offset circuit.
Key Touch LSI (HG52E35P)
By counting the time between first-key input signal FI and second-key SI from the keyboard unit, the key
touch LSI detects key velocity of 256-step. Then the LSI sends the CPU the note number and its velocity
data.
CRDB
CWRB
CKI
CCSB
RESB
CD0
CD7
CA0 ~ CA2
First contact
Second contact
KC0
KC7
FI0
FI7
SI0
SI7
Key input signal
Key scan signal
~
Data bus
Address bus
Key touch LSI
LSI106
HG52E35P Keyboard
FI
SI
KC
RD
WR
APO
A12
A14
CLOCK
RESET
Pin No. Terminal In/Out Function
1 SEL In Mode selection terminal. Connected to ground.
2 D.GND In Ground (0 V) source for internal digital circuit
3 NC Not used
4 DVDD In +5 V source for internal digital circuit
5 A.GND In Ground (0 V) source for internal analog circuit
6 R.OUT Out Right channel sound waveform output
7 A.VDD In +5 V source for internal analog circuit
8 A.VDD In +5 V source for internal analog circuit
9 R.REF In Reference voltage terminal. Connected to a capacitor.
10 L.REF In Reference voltage terminal. Connected to a capacitor.
11 L.OUT Out Left channel sound waveform output
12 A.GND In Ground (0 V) source for internal analog circuit
13 LRCK In Word clock (L/R separation signal) input.
14 LRSEL In Not used. Connected to ground.
15 SI In Sound data input
16 CLK In Bit clock input

— 9 —
Block diagram of DSP and DAC circuit
DSP
LSI105
HG51B155FD
Effect RAM (64K-bit)
LSI107
SRM2264LC90,10
Sound Source ROM
LSI103
TC5316200CP-C106
CE A0 ~ A19 D0 ~ D15
RA0 ~
RA19 RD0 ~
RD15
RA22
D0 ~ D7
A0 ~ A3
A13
A14
RD
WR
RESET
SOLP
BOK
WOK1
EA0 ~
EA12
ED0 ~
ED15
CS WE
OE
D0 ~ D15 A0 ~ A12
ECEB EOEB EWEB PG
X102
16.384MHz
DAC
LSI101
UPD6376CX
LOUT
ROUT
SOLP: Sound data
BOK: Bit clock
WOK1: Word clock
SI
CLK
LRCK
APO
CCSB
CRDB
CWRB
Pin No. Terminal In/Out Function
96 EWEB Out Write enable signal output for the effect RAM
98 EA13 Out Not used
106 EOEB Out Read enable signal output for the effect RAM
108 VCC7 In +5 V source
111 ECEB Out Chip select signal output for the effect RAM
113 ~ 117 Not used
118 VCC4 In +5 V source
119 GND4 In Ground (0 V) source
120 ~ 122 Not sued
123 ~ 130 ED0 ~ ED7 In/Out Data bus for the effect RAM
131 GND5 In Ground (0 V) source
132 ~ 134 Not used. Connected to ground.
135, 136 Not used

— 10 —
The following table shows the pin functions of the key touch LSI.
Filter Block
Since the sound signals from the DAC are stepped waveforms, the filter block is added to smooth the
waveforms.
AVDD
1K 1K 1K
C222(H)
C103(H)
AG AG
1K
AG
To main volume
-
+
IC105
M5218APR
10V22µ
C333(H)
Q107/108
2SC1740
18K
AVEE
50V1µ
From the DAC
Pin No. Terminal In/Out Function
1 REQB Out Interrupt request. Not used.
FI8 ~ FI10
SI8 ~ SI10
4 VCC In +5 V source
5 CRDB In Read enable signal
6 CWRB In Write enable signal
7 CCBB In Chip select signal
8, 9, 11 T, STBY, W In Not used. Connected to +5 V.
10 RESB In Reset signal
12 CKI In 10 MHz clock input
13, 14 TMD, TST In Not used. Connected to ground.
15 CKO Out Not used
16 GND In Ground (0 V) source
17 XIN In Not used. Connected to ground.
18 XOUT Out Not used
19 TRES In Not used. Connected to ground.
20 ~ 23, 25 ~ 28 CD0 ~ CD7 In/Out Data bus
24 GND In Ground (0 V) source
29 ~ 31 CR0 ~ CR2 In Address bus
32 VCC In +5 V source
33 ~ 39, 41 ~ 43 FI0 ~ FI7,
53 ~ 55, 57 ~ 59 SI0 ~ SI7
40 VCC In +5 V source
44 ~ 47, 49 ~ 52 KC0 ~ KC7 Out Key scan signal
48, 56 GND In Ground (0 V) source
64 VCC In +5 V source
In Key input signal. Connected to + 5 V.2, 3, 60 ~ 63
In Key input signal

— 11 —
Power Amplifier (LA4598)
The power amplifier is a two-channel amplifier with standby switch. The following figure shows the inter-
nal diagram of the amplifier.
Internal Diagram of LA4598
6
5
8
7
10
11 13
12
9
4
1
3
2
Input
Amp. Pre-drive
Amp. Power
Amp.
TSD protector
Stand by
Bias circuit
Input
Amp. Pre-drive
Amp. Power
Amp.
Ch1 IN
Ch1 N.F.
Pre GND
D.C.
Ch2 IN
Ch2 N.F.
Ch2 B.S.
Ch1 OUT
Power GND
VCC
Standby
Ch2 OUT
Ch2 B.S.
Power Supply Circuit
The power supply circuit generates six voltages as shown in the following table. VDD voltage is always
generated. The others are controlled by APO signal output from the CPU.
Name Voltage For operation of
VDD +5 V CPU, Reset IC, Working strage RAM
DVDD +5 V DSP, Key controller, Sound source ROM, Effect RAM, DAC, KO siginal generator
AVDD +5 V DAC Filter
LVDD +4.5 V LED Driver
VCC +9 V Pilot lamp
VC +9 V Power amplifier

— 12 —
M617T-KY2M
M617T-KY1M
JB1 JB2 JB3 JB4 JB5 JB6 JB7 JB8 JB9 JB10 JB11 JB12 JB13 JB14 JB15 JB16
JG1 JG2 JG3 JG4 JG5 JG6 JG7 JG8 JG9 JG10 JG11 JG12
JG1 JG2 JG3 JG4 JG5 JG6 JG7 JG8 JG9 JG10 JG11 JG12
JF3 JF2 JF1
DVDD
BENDER
DG
Bender
Volume
JE5
JE4
JE3
JE2
JE1
AG
L OUT
R OUT
R IN
L IN
JE5
JE4
JE3
JE2
JE1
JCM719-MA2M
Main Volume
LG
PWLD
POWER
KI1 KI2 KI3 KI4 KI5 KI6 KI7
La Lb
Lc
Ld Le
Lf
Lg Lp
CLK
KO9
KO
RESET
DVDD
DG
JC1 JC2 JC3 JC4 JC5 JC6 JC7 JC8 JC9 JC10 JC11 JC12
JD1 JD2 JD3 JD4 JD5 JD6 JD7 JD8 JD9 JD10 JD11 JD12
JC1 JC2 JC3 JC4 JC5 JC6 JC7 JC8 JC9 JC10 JC11 JC12
JD1 JD2 JD3 JD4 JD5 JD6 JD7 JD8 JD9 JD10 JD11 JD12
JA1 JA2 JA3 JA4 JA5 JA6 JA7 JA8 JA9 JA10 JA11 JA12 JA13 JA14 JA15 JA16
FI1 FI2 FI0
SI0 SI1 SI2 SI3
FI3
KC0 KC1 KC2 KC3 KC4 KC5 KC6 KC7
KC0 KC1 KC2 KC3 KC4 KC5
FI4
SI4
KC6 KC7
SI5 SI6 SI7
FI5 FI6 FI7
JB1 JB2 JB3 JB4 JB5 JB6 JB7 JB8 JB9 JB10 JB11 JB12 JB13 JB14 JB15 JB16
JA1 JA2 JA3 JA4 JA5 JA6 JA7 JA8 JA9 JA10 JA11 JA12 JA13 JA14 JA15 JA16
DC JACK
PHONE/OUTPUT
ASSIGNABLE JACK
MIDI IN
MIDI OUT
BATTERY
COMPARTMENT
BATT+
BATT-
JCM719-MA1M
JCM719-CN1M
JCM719-CN2M
LC1 LC2 LC3 LC4
Lp Lg
Lf
Le Ld
Lc
Lb La
WIRING DIAGRAM

— 13 —
MAJOR WAVEFORMS
1
2
1Main clock pulse
HD6433298A36P pin 7
2DSP clock pulse
HG51B155FD pin 12
3
5
3POWER signal
HD6433298A36P pin 13
4APO signal
HD6433298A36P pin 3
4
5RESET signal
HD6433298A36P pin 11
Power switch ON
6
6LED segment signal LD0
HD6433298A36P pin 31
7LED segment signal LD3
HD6433298A36P pin 34
7
Display: "0.0"
8
8Key scan signal KC0
HG52E35P pin 44
9Key scan signal KC1
HG52E35P pin 45
9
0
A
0Key scan signal KC2
HG52E35P pin 46
AKey scan signal KC3
HG52E35P pin 47
B
BBit clock BOK
UPD6376CX pin 16
CL/R clock WOK1
UPD6376CX pin 13
C
D
E
DSound data SOLP (Note OFF)
ESound data SOLP (Note ON)
UPD6376CX pin 15
F
FButton scan signal KO0
IC304: TC74HC174AP pin 2
GButton scan signal KO1
IC304: TC74HC174AP pin 5
G
H
I
HButton scan signal KO2
IC304: TC74HC174AP pin 7
IButton scan signal KO3
IC304: TC74HC174AP pin 15
JDAC output
UPD6376CX pin 11
KDAC output
UPD6376CX pin 6
J
K
Tone: No. 78
Key: A4
Touch response: OFF
Digital effect: OFF
Volume: Maximum
LPower amp. input
LA4598 pin 10
MPower amp. input
LA4598 pin 6
L
M

— 14 —
PCB VIEW AND MAJOR CHECK POINTS
JE
JE
0
W
51
1
JF
5
321
BK
17
R
1JC
12
12 11
JD
JA 16
JB
1
W
BL
R251
R252
R253
R254
R255
R256
R257
R258
R259
R260
R283
R282
R281
R280
R279
R278
R277
R276
R220
R221
R222
R223
R224
R225
R226
R227
R228
R229
R230
R231
R232
R233
R234 R262
R263
R266
R264
R265
R236 R237 R238
R241 R240 R239
R244 R246 R247 R248
R271 R272 R273 R275
R245 R243 R235 R242
R268 R267 R269
R158 R140 R141 R139
R150 R151 R152 R153 R154 R155 R156 R157
R126
R125
R124
R123
R129
R128
R131
R130
100
100
100
100
5
5
5
5
5
5
75
75
125
125
R195
R194
R193
R192
R219 R218
R250 R249
R103 R102
175
175
300 300
300
R114 R116 R115
175 175
R199
R198
R197
C119
C118
C131
C130
225
125
100
75
100
75
5
150
75
75
R168
R163
5
175
200 300 150
200
R184
R183
R182
R181
R178
R179
R180
175250
200
275
250275
225 250
175
300
100
100
225
175
100 125
5
5
200
100
100
100
75
75
100
150 150
150
225
100
275
125225
125
150
150
75
75
175
5
75
200
100
125
175 100
75
5150
75
150
100
150
75
5
250
75
150
5
100
125
175 5
75
100
C214
R161
C161
J104
C160
C162 R159
C188
C136
R143
C135
FB107
C137
R136
C189
1
C195
17 JB
C173 C172 C163
W
L111
C179
C178
R188
LSI105
R274
L110
PR
BL
C199
125
100
75
150
5
5
75
125
C196
C184
FB113
FB114
C191 C190
R217
R216
X102
R210
C197
IC106 C192
C193
LSI106
LSI104
R207
C180
C187
C177
R206
C181
FB112
C186
C194
R215
R209
R208
250
R270
LVDD
JD 12 1JA16
C150 C149 C148
1
IC103
R135 C133 C132
C185
C152D106
R133
R261
R186
R187
R162
Q107 L108
C125
R144 R160
C153 R167
C126
R164 Q108
BBEE
FB104
C171
C122
C171
C159
C124
C170
LSI101
IC107
R172
R171
R166
C176
C144
C143
C155
R169
IC105
C196
R174
R176
C198
C200
LSI107
EB EB EB
EB
E
B
E
B
E
B
E
B
Q116
Q115
Q114
Q113
C175
R202
R203
R204
R205
R201
Q112
Q111 Q110
Q109
R200
R191
R190
5
121 JC
MC101
C134
C167
C141
C142
R137
D108
C156
FB110
FB109
R175
X101
5
R177
C166
VDD
R149
C157
C102
R138
Q106
C147
EB
C168
R165 R173
R142
R185
FB105 FB106
C213
C154
C174
C165
R170 R146
R145
C128 C129
R121
5
R120
C123
5
C164
C139
C138
100
IC104 C146
31
R147 R148
C145
R134
C140 D109
D102
C104
C182
L101
L102
BK R
PZ
5 5
R108
D107
R293
Q105
EB
Q122
C211
R294
Q121
IC101
R295
31
BE
BE
C212
J102
FB102 FB103
R111
R112
L107
J103
C117
C114
C115
L106
R118
C107
R113
C116R117
C111
C108
C113
R291
R110
AVDD
C127
C110
VC
D105
Q104
D112
C120
R127
R132
C121
D101
R292
C103
DVDD R106 Q103 E
D111
VCC
B
C112
E
E
EE
E
R104
R105
C101
Q101
Q102
B
L103
O
W
PS
L104
FB111
EF101
EF102
1
2
3
JF
NO.
JE 15
D104
J101
D103
L121
C105
MAIN VOL
VR101 5JE 1
312
33
3
R214 R212
R211R213
LSI103
LSI102
EF103
MC102
IC102
GR
GR
202123 23
6
7
3
5
1
4
2
13 12 14 15

— 15 —
SCHEMATIC DIAGRAMS
PCB JCM719-MA1M
8 9 10 11
2
21
12
13
14 15
20
1
4
3
5
6 7
22
23

— 16 —
PCBs JCM719-CN1M, CN2M, MA2M
19 16 17
18

— 17 —
PCBs JCM617T-KY1M, KY2M

— 18 —
20
19
21
23
22
24
14
13
15 17
16
18
8
7
9
11
10
12
2
1
3
5
4
6
17
3-1
28-1
28-2
28-3
2-1
S-5
5-1
28-4
28-5
S-1
S-2
6-1
S-4
10
25
27
26
28
29
30
31
32
S-1
S-1
3-1
S-2
S-1
S-5
S-4
S-2
24
S-3
EXPLODED VIEW