Casio CTK-431 User Manual

ELECTRONIC KEYBOARDCTK-431CTK-431MIDI100 SONG BANK KEYBOARDMUSICAL INFORMATION SYSTEMSONG BANK CONTROLLERPOWER/MODEONOFFFINGEREDMAINVOLUMESYNCHRO/FILL

— 8 —MAJOR WAVEFORMS1 Clock pulseMSM6755C-17 pin 3212 +5 V source DVDDJB connector pin 43 APO signalJB connector pin 8234 Button scan signal KO6JA con

— 9 —3276451Top ViewPRINTED CIRCUIT BOARDSMain PCB JCM444-MA1MBottom View

— 10 —SCHEMATIC DIAGRAMSMain PCB JCM444-MA1M1542376

— 11 —Sub PCBs JCM444-MA2M/MA3M

— 12 —Keyboard PCBs JCM4911K-KY1M/KY2M

— 13 —LCDSegmentCommonCOM7COM6COM5COM4COM3COM2COM1SEG2COM11COM12SEG39SEG40COM10COM9COM14COM15COM16SEG11NCNCNCCOM16SEG3SEG4SEG5SEG6SEG7SEG8SEG9SEG10SEG

— 14 —EXPLODED VIEW181719226R-15127109111314151681223421204R-3R-53R-4R-2

— 15 —Notes: This parts list does not include the cosmetic parts, whichparts are marked with item No. "R-X" in the explodedview.Contact our

— 16 —Item Code No. Part Name Specification QRMain PCB1 6926 7070 PCB/ASSY (MA1M) M240832*1 1 BLSI1 2012 5603 LSI/MC (CPU) MSM6755B-17 1 ALSI2 2012 56

CASIO TECHNO CO.,LTD.Overseas Service DivisionNishi-Shinjuku Kimuraya Bldg. 1F5-25, Nishi-Shinjuku 7-ChomeShinjuku-ku, Tokyo 160-0023, Japan

CONTENTSSpecifications ...

— 1 —SPECIFICATIONSGENERALKeyboard: 49 standard-size keys, 4 octavesTones: 100Polyphony: 12 notes maximum (6 for certain tones)Auto accompanimentRhyth

— 2 —BLOCK DIAGRAMCPUMSM 6755C-17LSI1KeyboardButtonsLCDLCD DriverKS0066U-10BLSI3Reset ICIC1OscillatorX1, Q1Power Supply CircuitQ101 ~ Q103, D104Power

— 3 —KI0 KI1 KI2 KI3 KI4 KI5 KI6KO0 C2 G#2 E3 C4 G#4 E5 C6KO1 C#2 A2 F3 C#4 A4 F5KO2 D2 A#2 F#3 D4 A#4 F#5KO3 D#2 B2 G3 D#4 B4 G5KO4 E2 C3 G#3 E4 C5 G

— 4 —CPU (LSI1: MSM6755C-17)The CPU reads sound data from the ROM in accordance with the pressed key and the selected tone; the CPUcan read rhythm dat

— 5 —Pin No. Terminal In/Out Function74 ~ 77 DB4 ~ DB7 Out Data bus for the LCD driver78 NC9 — Not used79 LVCC In +5 V source80 ~ 84 KO8 ~ KO12 Out Te

— 6 —FILTER BLOCKSince the sound signals from the CPU is stepped waveforms, the filter block is added to smooth the waveforms.POWER AMPLIFIER (IC101:

— 7 —Item Measuring InstrumentVop voltage setting Voltmeter3) Equipment connection/ProcedureVop voltage settingInputConnectionInputPointInputSignalAdj