Canon PC940 Service Manual - Page 352

CHAPTER 11 TROUBLESHOOTING Code Cause • The main motor (M1) is fault. • The DC controller PCB is faulty. • The composite power supply PCB is faulty. • The DC controller PCB is faulty. ( ) • The scanner home position sensor (PS1) is faulty. The keys on the control panel are locked • The scanner/lens drive motor (M2) is faulty. • The DC controller PCB is faulty. without error code indication. Description • The rotation of the main motor deviates (indicated by MLOCK=0) for 1 sec or more while the main motor drive signal (MMD=1) is being generated. • The actual output value of the composite power supply high voltage is different from the setting value twice in succession. • The scanner home position is not detected within 10 sec after the scanner has turned on. • The scanner does not leave the home position after it has turned on. • The lens home position sensor (PS2) is faulty. • The scanner/lens drive motor (M2) is faulty. • The lens cable is faulty. • The DC controller PCB is faulty. • The scanning lamp (LA1) is faulty. • The DC controller PCB is faulty. • The composite power supply PCB is faulty. • The DC controller PCB is faulty. • The composite power supply PCB is faulty. • The frequency of the power supply is faulty. • The composite power supply PCB is faulty. • Data communication between the copier and the ADF (faulty). • The DC controller PCB is faulty. • The composite power supply PCB is faulty. • The lens hoe position is not detected after the lens has moved the maximum travel distance. • The lens does not leave the home position after it has turned on. • The lamp ON detection signal is not detected for 1 sec or more in the presence of the scanning lamp On signal. • The lamp ON detection signal is detected for 1 sec or more in the absence of the scanning lamp ON signal. • A fault in the communication between DC controller PCB and composite power supply PCB is detected. • The interval between zero-cross signals is in excess of the allowed interval. • The communication with the copier is interrupted for 5 sec or more; the communication is monitored at all times. • During a copying run, the +24 V power deviates from the control value by ±20%. COPYRIGHT © 1999 CANON INC. CANON PC800s/900s REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON) 11-87