Lexmark 11A4006 - Optra K 1220 B/W Laser Printer Service Manual page 55

3 Pick Roller
Gear
Pick Roller Feeds Paper but Stops or Jams at Input Feed Roll
FRU
1 Paper Path
2 Input Sensor
3 Paper Feed
Roll
4 Paper Feed
Motor
If the motor is operating correctly, check the pick
roller gear train. The pick roller gear contains a
clutch that allows rotation in only one direction. If it
is installed backwards, the pick roller cannot pick
the paper. If the pick roller gear is properly installed
but not working correctly, replace the gear.
To determine if the roller gear is positioned cor-
rectly, remove the paper tray and roll the pick roller
by hand. If you slide your hand toward the front of
the printer, the roller should rotate freely with little
resistance. If you slide your hand toward the rear of
the printer, the pick roller should resist rolling and
cause the pick motor to turn.
Action
Open the upper door, remove the print unit, and
check for loose debris in the paper path. Clean as
necessary.
Go to the "Input Sensor Service Check" on
page 2-21.
Check the paper feed roll for wear and replace as
necessary.
Be sure the paper feed motor is connected prop-
erly. Be sure the motor turns when you print a test
page.
If the motor does not turn, disconnect the motor
cable and check the impedance of the motor wind-
ings across the following motor connector loca-
tions:
CNRM-1 to CNRM-2 = approximately 30 Ohms
CNRM-3 to CNRM-4 = approximately 30 Ohms
If incorrect, replace the paper feed motor
Diagnostic Information 2-25