Canon PC400 Service Manual page 281

9. The main motor fails to rotate.
Cause
Main motor (M1)
DC controller/DC
power supply PCB
10. The copyboard fails to move.
Cause
Main motor (M1)
Copyboard,
Copyboard drive
assembly
DC controller/DC
power supply PCB
Copyboard drive
solenoid (SL2)
Step Checks
1 Set the meter to the '30VDC'
range. Does the voltage
between J903-1 (+) and J903-2
change from about 0 V to about
20 V according to the operation
of the main motor?
Step Checks
1 Is the main motor rotating?
2 Push the copyboard by hand.
Does it move smoothly?
3 Set the meter to the '200Ω'
range. Disconnect J902 from
the copyboard drive solenoid,
and measure the resistance
between terminals of SL2.
Is it about 120Ω?
CHAPTER 4 TROUBLESHOOTING MALFUNCTIONS
YES/NO
YES Replace the main motor.
NO Check the wiring from the
motor to the DC controller/
DC power supply PCB; if
normal, replace the DC
controller/DC power
supply PCB.
YES/NO
NO See "The main motor fails
to rotate."
NO Check the copyboard and
copyboard drive assembly.
YES Check the wiring from the
solenoid to the DC con-
troller/DC power supply
PCB; if normal, replace
the DC controller/DC
power supply PCB.
NO Check the solenoid (SL2).
Remedies
Remedies
4-5