Lexmark T520 - 20ppm 8MB Par USB Pcl6 Ps3 Ppds Service Manual page 92

4520-xxx
Tray X Low message displays when Tray X is full or has adequate
paper in the tray.
FRU
1 Paper Low Sensor
Assembly
Paper Low Sensor Flag
Tray X Option System
Board
Tray X Empty message displays when Tray X has paper in the tray.
FRU
1 Paper Out Sensor Flag
2 Paper Out Sensor (On
Option System Board)
2-64
Service Manual
Action
Run the Tray X Sensor Test and
check the sensor for proper
operation. If incorrect, check the
following:
Paper low sensor flag for smooth
and correct operation.
Paper low sensor for correct
installation on the autocompensator
housing.
Paper low sensor cable for signs of
cuts, pinched wiring or other
damage especially at connector J5
on the system board.
If no problem is found, replace the
paper low sensor assembly. If this
does not correct the problem,
replace the option system board.
Action
Check the paper out sensor flag for
correct operation and installation. If
correct, replace the option system
board. (The paper out sensor is
mounted on the system board).