Xerox Phaser 3100MFP Service Manual page 220

General Procedures and Information
Tray Empty Sensor
Figure 11
The laser unit [A] has the tray empty sensor [B] built into it. The tray empty sensor detects the
presence or absence of paper. The sensor has an actuator that extends through a slot in the paper
tray bottom plate [C], so that the sensor is actuated when paper is placed in the upper tray.
When the upper tray runs out of paper, the actuator of the tray empty sensor moves into the slot
in the upper tray bottom plate. This informs the CPU that paper has run out.
6-72 04/08 Phaser 3100 MFP