Lexmark 4090-001 Service Manual page 20

4090-001
FRU
2 Paper Feed Motor
3 Gears
4 Feed Arm
Assembly
5 Paper Path
2-9
Action
A noisy or chattering motor or a motor that fails to
turn, can be caused by:
• An open or short in the motor
• An open or short in the motor driver on the
system board
• A bind in the paper feed mechanism
With the paper feed motor cable disconnected
from the system board, check for 5 to 10 ohms
between pin 1 and 4 on the motor cable.
If the reading is incorrect, replace the motor.
Check for motor pins shorted to the motor housing.
If you find a shorted pin, replace the motor. If the
failure remains, replace the system board.
Although the paper feeds in a forward direction
only, the paper feed motor turns in two directions.
If the paper feed motor turns in one direction only,
replace the system board.
Binds in the paper feed motor or gear train can
cause intermittent false paper jam errors. Remove
the paper feed motor and check the shaft for binds.
Also check for loose or worn motor gear.
Check for binds in the gear train and paper feed
mechanism by rotating the large feed roll by hand.
If you notice a bind, isolate it by removing one of
the small idler gears on the inside of the left side
frame. Replace any worn or binding gears or
rollers.
At the beginning of the paper feed operation, the
paper feed motor reverses momentarily to allow
the feed arm pawl to drop off the home position
notch in the left side frame. If the pawl fails to drop
off the notch, check the feed arm assembly for
binds, and worn or broken parts.
Perform the 'Paper Path Service Check' on page
2-10, starting at Step 1.