Page 1
CTK-431
INDEX
100 SONG BANK KEYBOARD
MUSICAL INFORMATION SYSTEM
SONG BANK CONTROLLER
POWER/MODE
ON
OFF
FINGERED
CASIO CHORD
NORMAL
MAIN
VOLUME
PHONES/ DC 9V
OUTPUT
SYNCHRO/
START/
FILL-IN
STOP
TEMPO CHORD BOOK
ACCOMP VOLUME
OUTIN
MIDI
M
m 7 M7 dim
01234
56789
aug sus4 -5 add9 CLEAR
SONG BANK
MAIN VOLUME
TONE
RHYTHM
STATUS
TEMPO
MUSICAL INFORMATION SYSTEM
TONE SONG BANK
RHYTHM
TRANSPOSE/
TUNE/MIDI
REW STOP FF
LEFT
ON/OFF
SONG BANK CONTROLLER
P
L
A
Y
ELECTRONIC KEYBOARD
RIGHT
ON/OFF
E
S
U
/
A
P
CTK-431
Page 2
CONTENTS
Specifications ................................................................................................................................... 1
Block Diagram.................................................................................................................................. 2
Circuit Description ............................................................................................................................ 3
Adjustment ....................................................................................................................................... 7
Major Waveforms ............................................................................................................................. 8
Printed Circuit Boards ...................................................................................................................... 9
Schematic Diagrams ...................................................................................................................... 10
Exploded View ............................................................................................................................... 14
Parts List ........................................................................................................................................ 15
Page 3
SPECIFICATIONS
GENERAL
Keyboard: 49 standard-size keys, 4 octaves
Tones: 100
Polyphony: 12 notes maximum (6 for certain tones)
Auto accompaniment
Rhythm patterns: 100
Tempo: Variable (236 steps, = 20 to 255)
Chords: 2 fingering methods (CASIO CHORD, FINGERED)
Rhythm controller: START/STOP, SYNCHRO/FILL-IN
Accomp volume: 0 to 9 (10 steps)
Song bank
Tunes: 100
Controllers: PLAY/PAUSE, STOP, REW, FF, LEFT ON/OFF, RIGHT ON/OFF
Musical dictionary
Name display: TONE, RHYTHM, SONG BANK name/number, keyboard settings name/value
Tempo: Tempo value, metronome, synchro standby, beat indicator
Chord: Chord name, Chord form
Fingering: Fingering indicators, parts, pedal (The pedal indicator is for received MIDI
data only.)
Song bank status: PLAY, PAUSE, REW, FF
Staff: 4 octaves with sharp and flat indications
Keyboard: 4 octaves
MIDI: 5 multi-timbre receive
Other functions
Transpose: 12 steps (–6 semitones to +5 semitones)
Tuning: Variable (A4 = approximately 440 Hz ± 50 cents)
Volume: 0 to 9 (10 steps)
Terminals
MIDI terminals: IN, OUT
Phones/Output terminal: Stereo standard jack (Output is monaural.)
Output Impedance: 60 Ω
Output Voltage: 5 V (RMS) MAX
Power supply terminal: 9 V DC
Power supply Dual power supply system
Batteries: 6 AA-size batteries
Battery life: Approximately 2 hours (SUM-3/R6P)/4 hours (AM3/LR6)
AC adaptor: AD-5
Auto power off: Turns power off approximately six minutes after last key operation. Can be
disabled manually.
Speaker output: 3.0 W (Output is monaural.)
Power consumption: 9 V --- 7.5 W
Dimensions (HWD): 958 × 310 × 132 mm (37-3/4 × 12-3/16 × 5-3/16 inches)
Weight: Approximately 3.5 kg (7.7 lbs) (without batteries)
ELECTRICAL
Current drain with 9 V DC:
No sound output 200 mA ±20 %
Maximum volume 750 mA ±20 %
with 12 keys C1 to B1 pressed in Synth-Lead 1
Volume: 9 (Max.)
Phone output level (Vrms with 8 Ω load each channel):
with key A4 pressed in Synth-Lead 1 95 mV ±20 %
Speaker output level (Vrms with 4 Ω load each channel):
with key C4 pressed in Synth-Lead 1 1050 mV ±20 %
Output level (Vrms with 47 KΩ load each channel):
with key C1 pressed in Synth-Lead 1 1100 mV ±20 %
Minimum operating voltage: 5.7 V
— 1 —
Page 4
— 2 —
CPU
MSM 6755C-17
LSI1
Keyboard
Buttons
LCD
LCD Driver
KS0066U-10B
LSI3
Reset IC
IC1
Oscillator
X1, Q1
Power Supply Circuit
Q101 ~ Q103, D104
Power Amp.
LA4598
IC101
Filter
Q105
Speaker
(L)
Speaker
(R)
Phones/Output
VC
AVDDVCC DVDD
APO
MD0 ~ MD7
MA0 ~ MA17
DC + 9 V IN
DB4 ~ DB7
COM1 ~ COM16
SEG1 ~ SEG40
RS
R/W
E
KO8 ~
KO12
KI0 ~ KI6
KO0 ~ KO7
ROM(2M-bit)
UM23C2101M
7384/Q
LSI2
Power Switch
BLOCK DIAGRAM
Page 5
CIRCUIT DESCRIPTION
KEY MATRIX
KI0 KI1 KI2 KI3 KI4 KI5 KI6
KO0 C2 G#2 E3 C4 G#4 E5 C6
KO1 C#2 A2 F3 C#4 A4 F5
KO2 D2 A#2 F#3 D4 A#4 F#5
KO3 D#2 B2 G3 D#4 B4 G5
KO4 E2 C3 G#3 E4 C5 G#5
KO5 F2 C#3 A3 F4 C#5 A5
KO6 F#2 D3 A#3 F#4 D5 A#5
KO7 G2 D#3 B3 G4 D#5 B5
KO8 —+0
KO9 321
KO10 654
KO11 98
KO12 FF Right
7
Chord
Play/
Pause
Tempo Tempo Volume Volume
Down Up Down Up
Start/ Synchro/ Chord Accomp
Stop Fill-in Book Volume
Transpose/ Song
Tune Bank
Rhythm Tone
Fingered CASIO Normal Power Off
Stop Left Rewind
NOMENCLATURE OF KEYS
C#2 D#2 F#2 G#2 A#2 C#3 D#3 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
C2
D2 E2 F2 G2 A2 B2 C3 D3 E3 F3 G3 A3 B3 C4 D4 E4 F4 G4 A4 B4 C5 D5 E5 F5 G5 A5 B5 C6
— 3 —
Page 6
CPU (LSI1: MSM6755C-17)
The CPU reads sound data from the ROM in accordance with the pressed key and the selected tone; the CPU
can read rhythm data simultaneously when a rhythm pattern is selected. Then it provides the left and the right
channels’ waveforms separately, by converting the data into the waveforms with two built-in DACs. The CPU
also controls key and button input. The following table shows the pin functions of LSI1.
Pin No. Terminal In/Out Function
1 MA14 Out Address bus
2, 3 NCO — Not used
4 ~ 19 MA0 ~ MA13 Out Address bus
13 MRDB Out Read enable signal
17 MCSB — Not used
20 ~ 27 MD0 ~ MD7 In/Out Data bus
28, 29 NC1, NC2 — Not used
30 DGND In Ground (0 V) source
31 DVCC In +5 V source
32, 33 XTLO, XTLI In/Out 20 MHz clock input/output
34 NC3 — Not used
35 RSTB In Reset signal input
36 P24/RXD — MIDI signal input
37 P25/TXD — MIDI signal output
38 NMI In Power ON signal input. Connected to +5 V.
39 APO Out APO (Auto Power Off) signal output
40 NC4 — Not used
41 REFH Out Terminal for the internal DAC
42, 43 NC5, NC6 — Not used
44 DAOR Out Sound waveform signal output
45 NC7 — Not used
46 AVdac In +5 V source for the internal DAC
47 DAOL Out Left channel sound waveform output
48 REFL Out Terminal for the internal DAC and ADC
49 AGdac In Ground source for internal DAC
50 AGadc In Ground source for internal ADC
51 ANI In Not used
52 AVadc In +5 V source for the internal ADC
53 NC8 — Not used
54 MOD0 In Mode selection terminal. Connected to +5 V.
55, 56 MOD1, MOD2 In Mode selection terminal. Connected to ground.
57 P40 — Not used
58 ~ 64 KI0/P30 ~ KI7/P36 In Terminals for key/button input signal
65 KI7/P37 — Not used
66 ~ 73 KO0/P50 ~ KO7/P57 Out Terminals for key scan signal
— 4 —
Page 7
Pin No. Terminal In/Out Function
74 ~ 77 DB4 ~ DB7 Out Data bus for the LCD driver
78 NC9 — Not used
79 LVCC In +5 V source
80 ~ 84 KO8 ~ KO12 Out Terminals for button scan signal
85 ~ 87 P65 ~ P67 — Not used
88 RS Out Control signal for the LCD driver
89 R/W Out Read/Write signal for the LCD driver
90 E Out Chip enable signal for the LCD driver
91 ~ 95 P73 ~ P77 — Not used
96 LGND In Ground source
97, 100 MA18, MA15 Out Address bus
LCD DRIVER (LSI3: KS0066U-10B)
The LCD driver can drive a dot matrix LCD having 40 segment and 16 common lines. The LSI contains 240
graphic symbols in the built-in character generator ROM, and stores 80 characters in the built-in display data
RAM. In accordance with command from the CPU, the LSI is capable of displaying up to 16 characters
simultaneously. The following table shows the pin functions of LSI3.
Pin No. Terminal In/Out Function
1 ~ 22,
63 ~ 80
23 VSS — GND (0 V) source
24, 25 OSC1, OSC2 In/Out external resistor connected determines the oscillation
26 ~ 30 V1 ~ V5 In Those voltages are used for generating the stepped
31, 32 LP, XCLS — Not used
33 VDD In DVDD (+5 V) source
34, 35 FR, DO — Not used
36 RS In
37 R/W In Read/Write terminal. High: read, Low: write
38 E In High: enable, the writing is done at fall edge.
39 ~ 42 DB0 ~ DB3 — Not used. Connected to GND (0 V)
43 ~ 46 DB4 ~ DB7 In/Out Data bus
SEG1 ~ SEG40 Out Segment signal output
Terminals for the built-in clock pulse generator. The
frequency.
LCD drive voltage input.
pulse of the LCD drive signals.
Data/command determination terminal.
High: data, Low: command
Chip enable signal.
Low: disenable
47 ~ 62 COM1 ~ COM16 Out Common signal/output
— 5 —
Page 8
FILTER BLOCK
Since the sound signals from the CPU is stepped waveforms, the filter block is added to smooth the waveforms.
Amp.
LA4598
Filter
Block
POWER AMPLIFIER (IC101: LA4598)
The power amplifier is a two-channel amplifier with standby switch.
The following table shows the pin function of IC101.
Pin No. Terminal In/Out Function
1 Power GND In Ground (0 V) source
2 Ch1 B.S. — Terminal for a bootstrap capacitor
3 Ch1 OUT Out Channel 1 output
4 VCC In +9 V source
5 Ch1 N.F. In Negative feedback input
6 Ch1 IN In Channel 1 output
CPU
MSM6755C-17
7 D.C — Terminal for a bootstrap capacitor
8 Pre GND In Ground (0 V) source
9 Stand by In Power control signal input. 0 V:Off, +9 V: On
10 Ch2 IN In Not used. Connected to ground (0 V)
11 Ch2 N.F. In Negative feedback input
12 Ch2 OUT Out Channel 2 output
13 Ch2 B.S. — Terminal for a bootstrap capacitor
14 NC — Not used
— 6 —
Page 9
ADJUSTMENT
MAIN PCB
1) Items to be adjusted:
Item Measuring Instrument
Vop voltage setting Voltmeter
2) Adjustment and Test Point Locations
(TOP VIEW)
TP1
(BOTTOM VIEW)
VR1
3) Equipment connection/Procedure
Input
Connection
36.6°
Input
Point
Eye
Input
Signal
Vop voltage setting
Set Voltmeter
Output
TP1
Adjust
VR1 Voltmeter TP1
Watching the LCD at a 36.6° angle to the horizontal, adjust Vop
voltage so that unenergized segments are seen dimly.
Output
Connection
Output
Point
Adjust for
Adjust for 4.1 ~ 4.0 V reading
on voltmeter under the
temparature 20 ~ 25 °C.
Make fine adjustment according to the following instruction.
LCD
— 7 —
Page 10
1
MAJOR WAVEFORMS
2
3
1 Clock pulse
MSM6755C-17 pin 32
4
5
4 Button scan signal KO6
JA connector pin 14
5 Button scan signal KO7
JA connector pin 15
2 +5 V source DVDD
JB connector pin 4
3 APO signal
JB connector pin 8
6
7
6 LCD common signal COM9
KS0066U-10B pin 55
7 LCD common signal COM10
KS0066U-10B pin 56
— 8 —
Page 11
Main PCB JCM444-MA1M
PRINTED CIRCUIT BOARDS
1
4
5
6
Top View
7
2
3
Bottom View
— 9 —
Page 12
Main PCB JCM444-MA1M
2
SCHEMATIC DIAGRAMS
3
4
6
7
1
5
— 10 —
Page 13
Sub PCBs JCM444-MA2M/MA3M
— 11 —
Page 14
Keyboard PCBs JCM4911K-KY1M/KY2M
— 12 —
Page 15
LCD
COM7
COM6
COM5
COM4
COM3
COM2
COM1
SEG2
COM11
COM12
SEG39
SEG40
COM10
COM9
COM14
COM15
COM16
SEG11
NC
NC
NC
COM16
SEG3
SEG4
SEG5
SEG6
SEG7
SEG8
SEG9
SEG10
SEG21
SEG22
SEG23
SEG24
SEG25
SEG26
SEG27
SEG28
SEG29
SEG30
SEG31
SEG32
SEG33
SEG34
SEG35
SEG36
SEG37
SEG38
SEG39
SEG40
SEG1
SEG12
SEG13
SEG14
SEG15
SEG16
SEG17
SEG18
SEG19
SEG20
SEG21
SEG22
SEG23
COM15
COM14
COM13
COM12
COM11
COM10
COM9
COM16
COM15
COM14
COM13
SegmentCommon
COM7
COM6
COM5
COM4
COM3
COM2
SEG1
COM1
SEG3
SEG2
SEG4
SEG5
SEG6
SEG7
SEG8
SEG9
SEG10
SEG21
SEG22
SEG23
SEG24
SEG27
SEG25
SEG26
SEG29
SEG30
SEG28
SEG31
SEG32
SEG33
SEG34
SEG35
SEG36
SEG37
SEG38
SEG39
SEG40
COM11
SEG39
SEG40
COM12
COM10
COM9
COM14
SEG11
COM15
COM16
SEG12
SEG13
SEG15
SEG16
SEG14
SEG17
SEG18
SEG19
SEG20
SEG21
SEG22
SEG23
NCNCNC
COM15
COM16
COM14
COM13
COM12
COM10
COM9
COM11
COM16
COM15
COM14
COM13
— 13 —
Page 16
9
12
11
10
22
EXPLODED VIEW
R-1
5
8
6
16
7
15
14
13
17
18
2
R-4
1
23
20
4
21
19
R-2
4
R-3
R-5
3
— 14 —
Page 17
PARTS LIST
CTK-431
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.
— 15 —
Page 18
Item Code No. Part Name Specification QR
Main PCB
1 6926 7070 PCB/ASSY (MA1M) M240832*1 1 B
LSI1 2012 5603 LSI/MC (CPU) MSM6755B-17 1 A
LSI2 2012 5611 LSI/MASK-ROM UM23C2101M-7384/Q 1 A
LSI3 2012 5935 LSI/LCD DRIVER KS0066U-10B 1 A
IC1 2012 1883 IC/MOS (RESET IC) RN5VD40AA-TR 2 B
Q1,Q2 2252 1239 TRANSISTOR 2SC4081T106Q 1 B
Q3 2250 1162 TRANSISTOR 2SA1576AT106R 1 B
VR1 2775 0994 POTENTIOMETER EVN-D8AA03B53 1 B
X1 2590 2100 OSCILLATOR/CERAMIC CSACS20.00MX040-TC 1 B
Sub PCB
2 6927 5070 PCB/ASSY (MA2,3M) M241005*1 1 B
IC101 2114 2891 IC/LINEAR (POWER AMP) LA4598 1 A
IC102 2252 1248 IC/POTOCUPPLER HCPL-261A 1 A
Q102 2250 1591 TRANSISTOR 2SB1237TV2R 1 A
Q103~Q105 2250 1592 TRANSISTOR 2SC1740STPR 3 A
Q101 2250 1593 TRANSISTOR 2SD1858TV2R 1 A
D101 2390 3021 DIODE/SHOTTKY SRT14 1 C
D102 2390 3018 DIODE 1T2 1 C
D104~D113 2390 1344 DIODE 1SS133T-77-T 10C
D103 2360 2044 DIODE/ZENER MTZJ6.2A-T77-T 1 A
J101 3612 0665 JACK (PHONE) YKB21-5006 1 B
J102 3501 7049 JACK (POWER) HEC2305-01-330 1 B
J103 3501 4816 JACK (MIDI) YKF51-5051 1 B
Keyboard PCBs
3 6926 7050 PCB/ASSY M140749*1 1 C
D701 - D749 2301 0101 DIODE 1S2473T-77-T 49B
Mechanical Parts
4 3831 0665 SPEAKER 10G42AFA 1 B
5 3335 6823 LCD LD-B10272E 1 B
6 6926 7200 RUBBER/INTERCONNECTOR M440584-2 2 C
7 6927 6040 SPACER/455A M440810-1 1 C
8 6927 6050 SPACER/455B M440811-1 1 C
9 6927 6060 FILM/LEXAN M440812-1 1 C
10 6927 5060 EL M340996*1 1 B
11 6909 5890 SWITCH/SLIDE KONB CSB-12D 1 B
12 6921 5031 KNOB M311859-1 1 B
13 6927 6070 RUBBER/BUTTON M240796-2 1 B
14 6927 6080 RUBBER/BUTTON M240797-2 1 B
15 6927 6090 RUBBER/BUTTON M240798-2 1 B
16 6927 6100 RUBBER/BUTTON M240799-2 1 B
17 6922 2720 KEY SET/LT WHITE M312118*1 3 A
18 6922 2730 KEY SET/LT WHITE M312118*2 1 A
19 6922 2740 KEY SET/LT BLACK 10P M111726-1 2 A
20 6926 0670 RUBBER/CONTACT M240549-1 3 A
21 6926 0680 RUBBER/CONTACT M240550-1 1 A
22 6906 9611 PANEL/DISPLAY M340789-2 1 C
23 6925 4500 COVER/BATTERY M340528*1 1 B
Accessory
6906 8752 STAND/NOTE M340629B*2 1 B
Notes: Q– Quantity per unit
R– Rank
— 16 —
Page 19
CASIO TECHNO CO.,LTD.
Overseas Service Division
Nishi-Shinjuku Kimuraya Bldg. 1F
5-25, Nishi-Shinjuku 7-Chome
Shinjuku-ku, Tokyo 160-0023, Japan
Loading...