Lexmark T520 - 20ppm 8MB Par USB Pcl6 Ps3 Ppds Service Manual page 99

4520-xxx
The elevator tray fails to stop at the correct position and continues
to drive into the bottom frame.
FRU
1 Lower Limit Switch
Lower Limit Switch Cable
2 High-Capacity Feeder
Control Board
The elevator tray down button does not operate. The tray moves to
the upper position.
Service Tip: Open the high-capacity feeder front door and check the
black rubber bumper attached to the door switch spring. Be sure the
rubber button is centered and not touching the sides of the hole or
the switch will not function properly.
FRU
1 Lower Limit Switch
Lower Limit Switch Cable
High-Capacity Feeder
Control Board
Action
Check continuity of the lower limit
switch. If incorrect, replace the
switch. If correct, check the switch
cable. If incorrect, replace the cable.
If correct, replace the high capacity
feeder option control board.
Disconnect the lower limit switch
cable and check the voltage at J2-1
(orange). The voltage measures
approximately +5 V dc. If incorrect,
replace the high capacity feeder
option control board.
Action
Check the lower limit switch to make
sure it is not closed (normally open).
If incorrect, replace the switch.
Check the lower limit switch cable for
a short between pins 1 and 2. If
incorrect, replace the cable. If
correct, replace the high capacity
feeder control board.
Diagnostic Information
2-71