Casio ML-3 Service Manual

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

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

*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 Ω load): 740 mV ± 20% with key C4 pressed in Flute tone Volume: Maximum Minimum Operating Voltage: 6.2 V

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

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

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.

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 DG GND 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

2 1 3 4 6 5 3 4 3� � � 4 Sound signal output MSM6521-13 pin29 Power amp output AN8053N pin 1 1 2 1� � � 2 Key scan signal KO0 MSM6521-13 pin39 Key scan signal KO7 MSM6521-13 pin46 5 Mic, amp. input 6 Mic. amp. output T4 Emitter 5 6 PCB VIEW AND MAJOR WAVEFORMS

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 with- out 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. PARTS LIST ML-3

M111832*1 1 B LSI1 2011 8057 LSI MSM6521-13 1 A IC1 2114 3269 IC AN8053N 1 A T1 2253 0448 Transistor 2SD1858Q,R-TV6-T 1 A T2 - T5 2220 1387 Transistor 2SC1740SQ-TP-T 4 B D1 2390 0371 Diode DSK10B-BT-T 1 B D2 2390 1323 Diode RB100A-T32-T 1 B D3 2360 1519 Zener diode MTZJ6.8A-T77-T 1 A D4/5 2390 1344 Diode 1SS133T-77-T 2 B XL1 2590 0742 Ceramic oscillator EFO-GC2175C3 1 B J1 3501 3731 Power jack HEC2305-01-250 1 A J2 3501 4382 Jack HSJ2000-01-010 1 B LED PCBs 2 6922 6890 LED PCB ass'y M605-LM1M M211795*1 1 C 2370 1043 LED KR3301X-J171K 19 B 3 6922 6900 LED PCB ass'y M605-LM2M M211796*1 1 C 2370 1050 LED KR3302X-J173K 13 B Mechanical Parts 4 4317 5081 Blank PCB JCM605-KY1 M211780A-1 1 C 5 3831 0378 Speaker EAS-8P149BD 1 B 6 6922 8850 Rubber button M211778-2 1 B 7 6909 5890 Slide contact CSB-12D 1 B 8 6922 6930 Slide knob M311280-4 1 B 9 6906 7203 Black key set, LNM32 M110553C-3 1 A 10 6922 6760 White key set, LNM32 M117817-1 1 A 11 6917 1080 Key contact rubber M310878-1 1 A 12 6906 7311 Battery cover M312197A*2 1 B Accessories 6922 8890 Mic. holder M312227-1 1 B 6922 8881 Mic. holder base M312242A*1 1 B 6923 2300 Microphone 4110-072-0-01 1 B 6925 4630 Console sheet M240480A-2 1 B Notes: Q – Used quantity R – Rank — 11 —