Sharp ER-A450T Service Manual - Page 29

Receipt feed motor: The motor rotates counterclockwise. Step No. 1 2 3 4 A ON ON OFF OFF Phase B C OFF ON OFF OFF ON OFF ON ON D OFF ON ON OFF Journal feed motor: The motor rotates clockwise. Step No. 1 2 3 4 A ON ON OFF OFF Phase B C OFF OFF OFF ON ON ON ON OFF D ON OFF OFF ON Note 1: ON = Conducting OFF = Not conducting Note 2: The step No. is performed by the internal process of TPRC1. • When the motor is locked, the circuit is connected to the CPU through MPCA6. 3) Print circuit PB RAM STRB1~STRB5 TPRC 1 LATCH SO SI CLOCK VHCOM Thermal printer head VRES VH +24V 8. Drawer drive circuit VRESC +24V 51 DR0 52 DR1 IC9 DRAW0 DRAW1 CPU TD62308F 50 DOSP R161 22K R163 C105 47K 1000P R162 4.7K +24V Drawer solenoid Fig. 8-1 The drawer is directly supported by the CPU. No action starts when the power supply is not steady as the output stage of the driver is pulled VP by VRESC signal. Drawer open and close is sensed with the microswitch provided in the drawer whose signal level is converted with R161 and R162 which is read directly by the CPU. 9. Key, display, time buzzer controls MPCA7 HTS1 STH1 SCK1 RESET INT2 POFF HTS STH SCK RESET HTS STH SCK RES1 CPU P11 P10 P12 RES LDRQ ERC SHEN P-OFF LDRQ ECR SHEN POFF VDD RES0 RES0 ST0~ST7 KR0~KR7 KR10,KR11 Key board G1~G10 a~g,DP Display VCC B BUZZER Driver Driver 2 RESET ST0~ST7 KR0~7,KR10,KR11 T0~T9 a~g,DP CKDC 8 Fig. 9-1 1) Power on sequence During service interruption, the CKDC8 senses POF within 500msec. When service interruption is cancelled by turning on the power, the CKDC8 cancels resetting of the CPU in the command mode. After initializing each port, the CPU reads the start condition (1 byte). POF RES1 SHEN LDRQ 1 2 Start condition Next command Fig. 9-2 After sampling POF High, the CKDC8 performs a mode scan and key scan at , then cancels resetting of the CPU. After being cancelled, the CPU initializes each port at and reads the start condition. After being cancelled, the CPU reads the start condition while it also sets the shift mode. If, however, the first starting is made in other than SRV mode after the CKDC8 resets the CPU without request from the CPU, the CKDC8 sets the start condition as if the start condition was made in SRV mode. 4 - 21