S/M CTK-480

sAm
VZTEh 2
IK
C[
M^[ /x[X
Xvbg
88 12•M^[
98 }o
89 NCAXgOX 99 p[JbV
XgOX /ATu uX
ON
OFF
POWER/MODE
FINGERED
CASIO CHORD
NORMAL
[h /pCv
¢
⁄
FILL-IN
VZTEh 1
START/
STOP
TEMPO
¢
⁄
TRANSPOSE/TUNE
MULTI FUNCTION DISPLAY
TONE RHYTHM SONG
0
5
|bvX bN
00 |bvt[W 10 bNc
22 tHbNXgbg 32 c@ 1
13 \tgbN 2 23 W Yc
14 tH[L[|bv 24 AVbhW Y
05 t@L[|bv 15 60's \E 25 et[W 35 {Tmo
1
6
2
7
18 50's bN 28 bv
19 VJSu[X 29 t@N
3
8
4
9
W Y /_X
TONE
RHYTHM
[sA /e » …
MELODY
ON/OFF
00 AClENClEingEW[N
01 « « fl
08 ‰Ø ı
09 º ˘–…Ł˜
10 WOx
„ si
15 AnEIG
16 twlGx Ł
17 F ‹ æ
18 si¨w›Ø Łl‘x
19 G^[eBi[
CTK-480
00 sAm 1
01 sAm 2
02 zL[gN
03 X^WIsAm
04 GNgbNsAm 1
05 GNgbNsAm 2
06 GNgbNsAm 3
07 GNgbNsAm 4
08 n[vVR[h
09 NuGNg
10 GNgbNIK 1
11 GNgbNIK 2
12 GNgbNIK 3
13 GNgbNIK 4
14 ‘ [‘IK
15 pCvIK
16 [hIK
17 AR[fBI
18 ohlI
19 n[jJ
20 KbgM^[
21 AR[XeBbNM^[
22 W YM^[
23 GNgbNM^[
24 ~[gM^[
25 fBXg[VM^[
26 Ebhx[X
27 GNgbNx[X
28 Xbvx[X
29 oW[
100 TONES
30 oCI
31 ‘F
32 n[v
33 XgOX 1
34 XgOX 2
35 XgOX 3
36 VZXgOX 1
37 VZXgOX 2
38 NCA
39 {CX
40 gybg
41 ‘[o
42 uXZNV
43 t‘z 1
44 t‘z 2
45 uX 1
46 uX 2
47 VZuX 1
48 VZuX 2
49 VZuX 3
50 \vmTbNX 60 VZ[h 1
51 AgTbNX 61 VZ[h 2
52 ei[TbNX 62 VZ[h 3
53 I[{G
63 VZJIy
54 Nlbg 64 VZpbh 1
55 sbR
65 VZpbh 2
56 t[g
66 VZpbh 3
57 R[_[
67 OXn[jJ
58 t[gATu 68 Jg[t@[
59 zCbX
69 VZx[X
01 o[h
02 |bvo[h
03 bv|bv
04 \Eo[h
06 16r[g
07 8r[g 1
08 8r[g 2
09 |bvX
11 X[bN
12 \tgbN 1
16 bN
17 wr[^
50 RHYTHMS
20 rbNoh
21 X[XCO
26 gX
27 fBXR
30 |J
31 }[‘
33 c@ 2
34 ^S
36 To
37 }{
38 o
39 ‘ ‘ ‘
40 Q
41 QG
42 XJ
43 ebNXbNX
44 tHN[
45 Jg[
46 SXy
47 A_j
48 obN
49
02 ' ¢¢I[KX‘
03 ACWOEOCX
04
05 h·
06 hf[
07 O[X[uX
20 SONG BANK
11
12
13 AvXŒ
14 T^E‘A
70 p[hbv
71 RY~bNTEh
72 TEhgbN
73 Xy[Xpbh
74 VZ SFX
75 ł˚„ 1 ( Ł¤ )
76 ł˚„ 2 (db )
77 ł˚„ 3 (F )
78 ł˚„ 4 (Cx[_[ )
79 ł˚„ 5 (t@j[ )
80 XgOXsAm
81 XgOXGs
82 NCAGs
83 NCAIK
84 XgOXM^[
85 XgOXn[v
86 uXXgOX
87 oCupbh
90 x[X /sAm
91 x[X /Gs
92 x[X /oCu
93 x[X /KbgM^[
94 x[X /fBXg[VM^[
95 XgOX /sAm
96 XgOX /gybg
97 rutH
VOLUME SYNCHRO/
CTK-480
ELECTRIONIC KEYBOARD

CONTENTS
Specifications .......................................................................................................................... 2
Block Diagram ......................................................................................................................... 3
Circuit Description ................................................................................................................... 4
Troubleshooting ...................................................................................................................... 7
Major Waveforms .................................................................................................................... 8
Schematic Diagrams ............................................................................................................... 9
Printed Circuit Boards ........................................................................................................... 11
Exploded View ...................................................................................................................... 13
Parts List ............................................................................................................................... 15
GENERAL
SPECIFICATIONS
Number of keys: 61
Polyphonic:
12-note
Preset tones: 100
Auto-rhythms: 50, Tempo control: 40 to 255
Accompaniment:
CONCERT Chord, Fingered
Song bank:
20-tune
Tuning control:
440 Hz ± 50 cents
Built-in speakers:
4 inch dia. 1 W input rating: 2 pcs
Terminals:
Headphone Jack (Output impedance: 50 ohm, Output voltage: 4.6 V (rms) MAX
Power source:
2-way AC or DC source
AC: AC adapter
DC: 6D size dry batteries, Vehicle battery with DC adapter
Power consumption: 7.7 W
Dimensions(HWD): 90 × 910 × 322 mm (3-1/2 × 36-3/16 × 12-11/16 inches)
Weight:
3.9 kg (8 lbs) excluding batteries
ELECTRICAL
Current drain with 9 V DC:
No sound output 120 mA ± 30%
Maximum volume 650 mA ± 30%
with white keys C1 to G2 pressed in Synth-Lead 1
Volume: 9
Phone output Level (Vrms with 8 ohm load each channel):
with key E3 pressed in Synth-Lead 1 80 mV ± 30%
Sound Pressure (at 10 cm away from speaker):
with key E3 pressed in Synth-Lead 1
100 dB ± 10 dB
Minimum operating voltage:
6.0 V
— 2 —

BLOCK DIAGRAM
LED
Buttons
Output
CC1 ~ CC3
La ~ Lg,
Lp
KO8 ~
KO11
KI0 ~ KI7
— 3 —
Power Amp.
LA4598
IC101
VC VCC AVDD DVDD LVDD
Filter (L)
Q109
Filter (R)
Q110
APO
CPU
MSM 6755B-06
LSI101
Keyboard
Power Supply Circuit
Q101 ~ Q104, D108, D109
KO0 ~ KO7
DC+9V IN
Q105
Reset IC
IC102
Oscillator
X101, Q111

CIRCUIT DESCRIPTION
KEY MATRIX
KI0 KI1 KI2 KI3 KI4 KI5 KI6 KI7
KO0 C1 G#1 E2 C3 G#3 E4 C5 G#5
KO1 C#1 A1 F2 C#3 A3 F4 C#5 A5
KO2 D1 A#1 F#2 D3 A#3 F#4 D5 A#5
KO3 D#1 B1 G2 D#3 B3 G4 D#5 B5
KO4 E1 C2 G#2 E3 C4 G#4 E5 C6
KO5 F1 C#2 A2 F3 C#4 A4 F5
KO6 F#1 D2 A#2 F#3 D4 A#4 F#5
KO7 G1 D#2 B2 G3 D#4 B4 G5
KO8 0 1 2 3 4 Start/Stop
KO9 5 6 7 8 9
K10 Tone Rhythm
Song
Bank
Melody
On/Off
Tempo
Down
K11 Fingered CONCERT
Chord
Tempo
Up
Volume
Down
Normal
Volume
Up
Synchro/
Fill-In
Power Off
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 C#6 D#6 F#6 G#6 A#6
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 D6 E6 F6 G6 A6 B6
C7
— 4 —

AVDD
10
10 V 22 µ
+
CPU (LSI101: MSM6755B-06)
The CPU contains a sound data ROM and a DAC (Digital to Analog Convertor), and it provides left and right
channel sound waveforms in accordance with the pressed key and the selected tone.
The following table shows the pin functions of LSI101.
Pin No. Terminal In/Out Function
1 ~ 29 MA14 ~ NC2 — Not used.
30 DGND In Ground (0V) source
31 DVCC In +5V source
32, 33 XTLO, XTLI In/Out 20MHz clock input/output
34 NC3 — Not used. Connected to ground.
35 RSTB In Reset signal input
36 P24/RXD — Not used. Connected to +5V.
37 P25/TXD — Not used.
38 NMI In Power on signal input
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 Right channel sound waveform output
45 NC7 — Not used.
46 AVdac In +5V source for the internal DAC and ADC
47 DAOL Out Left channel sound waveform output
48 REFL Out Terminal for the internal DAC and ADC
49 AGdac In Ground source for the internal DAC
50 AGadc In Ground source for the internal ADC
51 ANI — Not used. Connected to ground.
52 AVadc In +5V source for the internal ADC
53 NC8 — Not used. Connected to +5V.
54 MOD0 In Mode selection terminal
55, 56 MOD1, MOD2 In Mode selection terminal
57 KO9/P40 In Power source detection signal input
58 ~ 65 KI0/P30 ~ KI7/P37 In Terminals for key/button input signal
66 ~ 73 KO1/P50 ~ KO8/P57 Out Terminals for key scan signal
74 ~ 77 P20 ~ P23 Out Terminals for button input signal
78 NC9 — Not used.
79 LVCC In +5V source
80 ~ 82 CC1 ~ CC3 Out LED common signal output
83 ~ 87 — — Not used.
88 ~ 95 La ~ Lg, Lp Out Not used.
96 LGND In Ground (0V) source
97 ~ 100 — — Not used.
FILTER BLOCK
Since the sound signal from the CPU is a stepped waveform, the filter block is added to smooth the waveform.
To main volume
+
AG
16 V 10 µ
2.2 K
2SC1740SQ
10 K
C221B (A)
C332(H)
AG AG AG AG
— 5 —
10 K 10 K
C152 (H)
33 K
From the CPU

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 (0V) source
2 Ch1 B.S. — Terminal for a bootstrap capacitor
3 Ch1 OUT Out Channel 1 output
4 VCC In +9V source
5 Ch1 N.F. In Negative feedback input
6 Ch1 IN In Channel 1 input
7 D.C. — Terminal for a decoupling capacitor
8 Pre GND In Ground (0V) source
9 Stand by In Power control signal input. 0 V: Off, +9 V: On
10 Ch2 IN In Channel 2 input
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
LED DRIVING
La~Lg, Lp
LVDD
LG
CPU
LSI01
MSM6755B
CC1~CC3
Q106~Q108
LED Driver
— 6 —

INITIAL RESET CIRCUIT
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.
VDD
Battery Set
Reset IC
RE5VA35A
IC102
RESET
CPU
MSM 6755B-06
LSI101
TROUBLESHOOTING
Nature of Trouble Faulty Block Cause/Remedy
No power Power supply circuit Faulty IC101. Replace IC101.
Faulty D106 ~ D109. Replace D106 ~
D109.
Faulty Q101 ~ Q104. Replace Q101 ~
Q104.
Power switch
Poor contact. Clean the contacts.
Power jack (J101)
Open J101 or poor soldering. Replace
J101 or resolder.
No sound at all Power Amp (IC101: LA4596) Open or shorted IC101. Replace IC101.
CPU (LSI101: MSM6755B-06) Faulty LSI101. Replace LSI101.
Oscillator Faulty Q111. Replace Q111.
Open X101. Replace X101.
Certain keys or switches
do not function
A certain key or switch
does not function
Key and switch matrix
CPU (LSI101: MSM6755B-06)
Key and switch matrix
Open circuit on KO or KI line.
Replace keyboard PCB assembly.
Faulty LSI101. Replace LSI101.
Dust on the contact.
— 7 —

MAJOR WAVEFORMS
0.1 s
20 µs
CH1
1 2
CH1
CH1 5V BWL
1 RESET signal
IC102 pin 1
CH1
1V
2 Main clock pulse
MSM6755B-06 pin 32
BWL
10 µs
1ms
CH1
5
CH1
3
4
CH2
6
CH2
CH1 5V CH2 5V
BWL
CH1 1V CH2 1V
BWL
3 Key scan signal KO10
MSM6755B-06 pin 76
4 Key scan signal KO11
MSM6755B-06 pin 77
5 Sound signal output (L-ch)
MSM6755B-06 pin 47
6 Sound signal output (L-ch)
Q109 2SC1740SQ Emitter
1ms
1ms
7
CH1
9
CH1
8
CH2
0
CH2
CH1 1V CH2 1V
7 Sound signal output (R-ch)
MSM6755B-06 pin 45
8 Sound signal output (R-ch)
Q110 2SC1740SQ Emitter
BWL
— 8 —
CH1 1V CH2 1V
9 Sound signal output (R-ch)
LA4598 pin 3
0 Sound signal output (L-ch)
LA4598 pin 12
Tone: Flute Ensemble (58)
Key: A3
Volume: 7
BWL

Main PCB KDM440-MA1M
SCHEMATIC DIAGRAMS
Notes:
1. All capacitance values are indicated in "µF" (p=10 -6 µF)
2. All resistance values are indicated in "Ω" (k=10 3 Ω, M=10 6 Ω).
1
7
5
2
10
9
6
8
3
4
— 9 —

Keyboard PCBs KDM6111K-KY1M/KY2M
Notes:
1. All capacitance values are indicated in "µF" (p=10 -6 µF)
2. All resistance values are indicated in "Ω" (k=10 3 Ω, M=10 6 Ω).
— 10 —

PRINTED CIRCUIT BOARDS
Main PCB KDM440-MA1M
4
3
2
1
7 5 6 8
10
9
Top View
Console PCB KDM6111K-KY1M
Top View
Console PCB KDM6111K-KY2M
Top View
— 11 —

Main PCB KDM440-MA1M
Bottom View
Console PCB KDM6111K-KY1M
Bottom View
Console PCB KDM6111K-KY2M
Bottom View
— 12 —

EXPLODED VIEW
9
8
10
11
R-1
7
6
R-2
R-3
3
4
1
2
5
4
15
12
14
16
13
R-4
16
15
R-5
— 13 —

PARTS LIST
CTK-480
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.

FOB Japan
N Item Code No. Parts Name Specification Q N.R.Yen R
Unit Price
MAIN PCB ASSEMBLY
IC101 2114 2891 Monolithic IC LA4598 1 A
IC102 2105 5922 IC RE5VL40AA-TZ 1 A
LSI101 2012 3486 LSI, CPU MSM6755B-06 1 A
Q101 2251 0469 Transistor 2SB1237Q 1 B
Q102 2220 1387 Transistor 2SC1740Q 1 B
Q103/104 2253 0448 Transistor 2SD1858Q 2 B
Q105 2200 2449 Transistor 2SA933SQ 1 B
Q106 - 111 2220 1387 Transistor 2SC1740Q 6 B
D101 2360 1729 Zener diode MTZJ5.1A 1 B
D103 2390 2828 Diode RB441Q-40T 1 B
D105 2390 2828 Diode RB441Q-40T 1 B
D106 2390 2408 Zener diode 1FW143N 1 B
D107 2390 2828 Diode RB441Q-40T 1 B
D108 2360 2002 Zener diode MTZJ5.6BT 1 B
D109 2360 2002 Zener diode MTZJ5.6BT 1 B
D110 - 129 2390 2828 Diode RB441Q-40T 20 B
D130 2390 2828 Diode RB441Q-40T 1 B
LED101 2370 1106 LED MPR3338S-B99 1 B
LED102 2370 1309 LED LB603VF1 1 B
X101 2590 1526 Ceramic oscillator EFO-EN2005C4 1 B
J101 3501 7046 Power jack HEC2305-01-330 1 A
J102 3612 0665 Phones jack YKB21-5006 1 C
CONSOLE PCB ASSEMBLY
D701 - 725 2301 0101 Diode 1SS2473 25 B
D731 - 766 2301 0101 Diode 1SS2473 36 B
MECHANICAL PARTS
1 6909 5890 Slide contact CSB-12D 1 B
2 6925 1560 Key contact rubber, 6-contact M340418-1 1 B
3 6925 1630 Key contact rubber, 14-contact M340417-1 1 B
4 3831 0770 Speaker S10JA13A 2 B
5 6925 1260 PCB ass'y, MA1M 6925 1260 M140403*1 1 B
6 6925 1890 Battery cover M340485*1 1 B
7 6921 5030 Slide knob M311859-1 1 B
8 6922 2720 White key set, 7-Key M312118*1 4 A
9 6922 2730 White key set, 8-Key M312118*2 1 A
10 6922 2750 Black key set, 5-Key M111726-2 1 A
11 6922 2740 Black key set, 10-Key M111726-1 2 A
12 6922 4000 Key contact rubber, 31-contact M111765-1 1 B
13 6922 3990 Key contact rubber, 30-contact M111764-1 1 B
14 6925 1310 PCB ass'y, KY M140402*1 1 B
15 6925 1600 Plastic foot M440346-1 2 B
16 6925 1620 Rubber foot M440366-1 2 B
— 15 —

MA0600761A