Casio CTK-631 Service Manual

Also see for CTK-631: User guide User guide

Contents

Casio CTK-631 Service Manual Manual pdf 7 page image

— 5 —Reset ICIC2RN5VD40AADSPLSI2HG51B277FB-1VDDReset signalTo power supply circuitVDDBattery setRESETVDDPOWERFrom power switchNMIAPOPLECPULSI1GT913F(T)SCKOF#3 G#3 A#3 C#4 D#4 F#4 G#4 A#4 C#5 D#5 F#5 G#5 A#5F3 G3 A3 B3 C4 D4 E4 F4 G4 A4 B4 C5 D5 E5 F5 G5 A5 B5 C6D#3C2 D2 E2 F2 G2 A2 B2 C3 D3 E3 B6A6G6F6E6D6 C7C#3A#2G#2F#2D#2C#2 A#6G#6F#6D#6C#6KeySecond contact (2) First contact (1)FIKCSINote: Each key has two contacts,the first conatct (1) and second contact (2).POWER SUPPLY CIRCUITThe power supply circuit generates five voltages as shown in the following table. VDD voltage is alwaysgenerated. The others are controlled by APO signal from the CPU.NOMENCLATURE OF KEYSRESET CIRCUITWhen batteries are set or an AC adapter is connected, the reset IC provides a low pulse to the CPU. TheCPU then initializes its internal circuit, and clears the working storage RAM.When the power switch is pressed, the CPU receives a low pulse of POWER signal. The CPU sends APOsignal to the power supply circuit, also sends a reset signal to the DSP.Name Voltage For operation ofVDD +5 V CPU, Reset IC, DSP, Sound source ROM, Working storage RAM, Effect RAMDVDD +5 V LCD driver, Power jack, Sustain jack, MIDI jackAVDD +5 V DAC, FilterLVDD +5.6 V LCD dirverVCC +9 V Power amplifier, Pilot lamp