Lexmark Optra C710 Service Manual page 170

5016-001
E Paper size in tray 1 is not detected.
When media in Tray 1 reaches 50 or less sheets, the paper detect
lever turns on the paper detect sensor and displays Load Paper Tray
1.
FRU
1 Tray 1 Rear Paper
Guide
2 Paper Size Detect
Plate
Paper Size Detect
Plate Spring
3 CST Cable
Paper Size Detect
Sensor Board
Engine Board
2-104
Service Manual
Action
Check the rear paper guide in tray 1 for correct
installation and signs of damage to the paper
size detect flag. If the flag is broken, replace the
rear paper guide.
Check the paper size detect plate spring for
looseness or if it is broken. If broken, reconnect
or replace the spring.
Check the paper size detect plate for proper
operation. If incorrect, repair as necessary.
Check the continuity of the CST cable. If
incorrect, replace the cable.
Check the paper size detect sensor board for
correct operation. If incorrect, replace the
sensor board.
If the CST cable and size detect sensor board
are operating correctly, replace the engine
board.