Canon PC740 Service Manual - Page 113

OPERATIONS AND TIMING Code Cause • Scanner home position sensor (PS1; I= Li117. faulty) (keys on • Scanner motor (M2; faulty) control board • DC controller PCB (faulty) E2 : 0 • locked) Lens home position sensor (faulty) • Scanner motor (faulty) • Lens cable • DC controller PCB (faulty) E22L'i • Scanning lamp • Intensity sensor PCB (faulty) • DC controller PCB (faulty) • Composite power supply PCB (faulty) E214112 • DC controller PCB (faulty) 4 • Composite power supply (faulty) E26 if •Power supply frequency (faulty) • Composite power supply PCB (faulty) EOL• I nr13 • DC controller PCB (faulty) P(pC sfuoaCopw um Bpletplyryo) site • Scanning lamp (faulty) Description • The lens home position cannot be detected after the lens has traveled over its maximum distance. • The lens does not leave the lens home position. • The lens home position cannot be detected after the lens has traveled over its maximum distance. • The lens does not leave the lens home position. • Intensity adjustment fails to end within 10 sec after the scanning lamp has turned on. • The scanning lamp remains on for 5 sec during standby. • The scanning lamp remains off for 5 sec during copying. • An error is detected in the communication between the DC controller PCB and the composite power supply PCB. • The intervals in the zero-cross signals is greater than allowed. • The +24V power supply deviates from the control value by ±20% during copying. COPYRIGHT © 1994 CANON INC. CANON PC720/7401750770 REV.O AUG.1994 PRINTED IN JAPAN (IlAPRIME AU JAPON) 3 - 73