Casio ML-3 User manual

ELECTRONIC KEYBOARD
ML-3
ML-3
SONG BANK25 TONES
TEMPO TONE
RHYTHM
SEL.
1234
VOLUME
MELODY GUIDE
PLAY
DEMO
ANY-KEY PLAY
MODE
5
LIGHT ON/OFF
1
POPS WALTZ
ROCK 8 BEAT 16 BEAT DISCO SLOW ROCK FUNK SWING BOSSA NOVA SAMBA MARCH
RHYTHM
SONG
2 3 4 5 678910
1
10
POWER OFF
11 PIANO
12 ELEC PIANO
13 PIPE ORGAN
14 JAZZ ORGAN
15 ACCORDION
21 FLUTE
22 CLARINET
23 TRUMPET
24 HARMONICA

25 VIOLIN
31 BRASS ENS
32 SYNTH-BRASS
33 STRINGS
34 SYNTH-STRINGS
35 CHORUS
41 ELEC GUITAR
42 JAZZ GUITAR
43 VIBRAPHONE

44 CHURCH BELLS
45 BELLS
51 SYNTH-REED
52 WAW VOICE
53 METAL LEAD
54 ROCK DRUM
55 S.E.
1 FRÈRE JACQUES
2 JOY TO THE WORLD
3 OLD MacDONALD HAD A FARM
4 TWINKLE TWINKLE LITTLE STAR
5 MINUET(J.S.BACH )
6 LONDON BRIDGE
7 MICHAEL
8 MARY HAD A LITTLE LAMB
9 THE CAMPTOWN RACES
10 ODE TO JOY
STOP

CONTENTS
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Circuit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Schematic Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
PCB View and Major Waveforms. . . . . . . . . . . . . . . . . . . . . . . . . 9
Exploded View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

— 1 —
*Power ON Reminder
Power ON reminder is sudden audible and light signals, a short melody at maximum volume and lighting
up the illuminated keyboard for a few seconds.
Power ON reminder functions three minutes after the last operation, and it repeats every three minutes until
turning the switch off or restarting operations.
SPECIFICATIONS
General
Number of Keys: 32
Illuminated Keys: White and Black keys
Polyphonic: 2-note
Preset Tones: 25
Auto-Rhythms: 12
Demonstration Tunes: 10
Lesson Functions: 3 modes; Demo, Any-Key Play, Melody Guide
Built-In Speaker: 8.0 cm dia. 1.0 W Input Rating: 1 pce.
Terminals: Mic. Jack [Input Impedance: 20 kΩ
AC Adapter Jack (DC 7.5 V)
Power Source: DC: 5 AA size dry batteries
Battery life: Approx. 4 hours (SUM-3/R6P)
AC: AC adapter AD-1
Power ON Reminder*: 3 minutes after the last operation
Power Consumption: 1.5 W
Dimensions: 57 ×412 ×208 mm (HWD)
(2-1/4 ×16-3/8 ×8-1/4 inches) (HWD)
Weight: 0.95 kg (2.1 lbs) excluding batteries
Electrical
Current Drain with 7.5 V DC:
No Sound Output 44 mA ±20%
Maximum Volume 280 mA ±20%
with keys B3 and C4 pressed in Flute tone
Volume: Maximum, Rhythm: Rock,
Tempo: Maximum, Mic. input: 29 mV
Speaker Input Level (Vrms with 4 Ωload): 740 mV ±20%
with key C4 pressed in Flute tone
Volume: Maximum
Minimum Operating Voltage: 6.2 V

— 2 —
KO0~KO11
KI0~KI7
Illuminated Keyboard
Switches
Oscillator
XL1
Amplifier
AN8053N
IC1
Mic. amp.
T4, T5
Speaker
CPU
MSM6521-13
LSI1
LEDs
LX0~LX3
LY0~LY7
Power Supply Circuit
T1, D3
VDD 5.6V AVDD 5.6V
Filter
T3
Mic. input
BLOCK DIAGRAM
Nomenclature of Keys
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

— 3 —
LY0 LY1 LY2 LY3 LY4 LY5 LY6 LY7
LX0 C6 F5 E5 A4 G#4 C#4 C4 F3
LX1 B5 F#5 D#5 A#4 G4 D4 B3 F#3
LX2 A#5 G5 D5 B4 F#4 D#4 A#3 G3
LX3 A5 G#5 C#5 C5 F4 E4 A3 G#3
KI0 KI1 KI2 KI3 KI4 KI5 KI6 KI7
KO0 F3 F#3 G3 G#3 A3 A#3 B3 C4
KO1 C#4 D4 D#4 E4 F4 F#4 G4 G#4
KO2 A4 A#4 B4 C5 C#5 D5 D#5 E5
KO3 F5 F#5 G5 G#5 A5 A#5 B5 C6
KO4 Volume
Down Volume Up Light On/Off
KO5 Tone 1 Rhythm
Stop Tempo Down
KO6 Tone 2 Tone 3 Tone 4 Tone 5 Rhythm
Select Tempo Up
KO7 Melody
Guide Any Key Play Demo Play
CIRCUIT DESCRIPTION
Key Matrix
Keyboard LED Matrix

— 4 —
AVDD
AG AG AG
C11
C12
T2
2SC1740SQ
C9
R11
C10
R12 R13 R14
Pin No. Terminal In/Out Function
1 ~ 7 LY1 ~ LY7 Out Keyboard LED drive signal output
8 LVDD1 In +5 V source for the built-in LED driver
9 LGND2 In Ground (0 V) source for the built-in LED driver
10 ~ 13 LX0 ~ LX3 Out Keyboard LED drive signal output
14 ~ 17 LX4 ~ LX7 Out Not used.
18 LVDD2 In +5 V source for the built-in LED driver
19 GND2 In Ground (0 V) source
20, 21 COSI, COSO In/Out 21.725 MHz clock pulse input/output
22 VDD In +5 V source
23 GND1 In Ground (0 V) source
24 ~ 26 TEST1 ~ TEST3 In Not used. Connected to ground.
27 RESET In Reset signal input. Power OFF: 0 V, Power ON: +5 V
28 AVDD In +5 V source for the built-in DAC
29 OUT Out Sound waveform output
30 AGND In Ground (0 V) source for the built-in DAC
31 ~ 38 KI0 ~ KI7 In Input terminal for keys and switches
39 ~ 46 KO0 ~ KO7 Out Key and switch scan signal input
47 ~ 58 — — Not used.
59 LGND1 In Ground (0 V) source for the built-in LED driver
60 LY0 In Keyboard LED drive signal output
Filter Block
Since the sound signal from the CPU is a stepped waveform, the filter block is added to smooth the waveform.
CPU (LSI1: MSM6521-13)
Containing a sound data ROM and a DAC (Digital to Analog Converter), the CPU provides sound waveform
in accordance with the pressed key and selected tone. The CPU also drives LEDs in the illuminated keyboard
directly. The following table shows the pin functions of LSI1.

— 5 —
Nature of Trouble Faulty Block Checkpoint
No power Power Supply Circuit Base of T1 should receive +6 V.
Emitter of T1 should provide +5.6 V.
Power switch Switch contact.
Power Jack (J1) Jack contact.
No sound at all Power Amp.
(IC1: AN8053N) Pin 16 should receive +7.5 V when the power switch is turned on.
Voltage at pin 14 should drop at 0 V
when the power switch is turned on.
Check output signal of pin 1.
CPU (LSI1: MSM6521-13) Voltage at pin 27 should rise 0 V to 5.6
V when the power switch is turned on.
Pins 39 ~ 46 should provide pulses.
Pin 29 should have a sound signal when
a key is pressed.
Oscillator (XL1) Pins 20 and 21 of the CPU should
receive an ocsillation signal.
Keyboard LEDs don't
light up Keyboard LED
Keyboard LED Matrix Open circuit on LX or LY line.
A certain key or switch
does not function Key and Switch Matrix Dust on the contact.
Certain keys or switches
do not function Key and Switch Matrix Open circuit on KC or KI line.
R3 R4
R5
R1
D2
ON
OFF
Power Switch
DC +7.5 V
Input
GND DGGND AG
T1
2SD1858Q,R
D3
MTZJ6.8A
C3
R2
R6
C5 C4
D5
VDD +5.6V
AVDD +5.6V
Power Supply Circuit
The power supply circuit regulates a constant output voltage +5.6V by T1 and D4.
TROUBLESHOOTING

— 6 —
SCHEMATIC DIAGRAMS
JCM605-KY1M

— 7 —
JCM605-LD2MJCM605-LD1M

— 8 —
4
6
3
6
1
2
5
5
JCM607-MA1M/MA2M