Xerox 4400DT - Phaser B/W Laser Printer, Service Manual, Page: 120 / 503

Phaser 4400 Laser Printer Service Manual 3-23
Stack Height Sensor Checkout
2 Visually inspect the Output Tray Full Sensor Actuator.
Does the actuator moves freely and is it in good
condition (not broken or damaged)?
Go to step 3. Replace the
Output Tray
Full Actuator
(RRP 6.8 on
page 6-76 ).
3 1. Switch the printer power OFF.
2. Remove the Left Interface Cover (RRP 1.1 on
page 6-6 ), Left Cover (RRP 1.2 on page 6-7 ), and the
Left Plate (RRP 1.11 on page 6-16 ).
3. Disconnect P/J31 from the Engine Logic Board.
4. Switch the printer power ON.
5. On the Engine Logic Board, measure the voltage
between P31 pin 1 and frame ground.
Is the v3.3 VDC?
Go to step 5. Go to step 4.
4 On the Engine Logic Board, measure the voltage
between P/J28 pin 10 and frame ground.
Is the v3.3 VDC?
Replace the
Engine Logic
Board (RRP
9.3 on
page 6-89 ).
Replace the
LVPS (RRP
9.5 on
page 6-91 ).
5 1. Switch the printer power OFF.
2. Reconnect P/J31 to the Engine Logic Board. Switch
the printer power ON.
3. On the Engine Logic Board, measure the voltage
between P/J31 pin 3 and frame ground.
Is there +3.3 VDC between P/J31 pin 3 and frame
ground when the Output Tray Full Sensor is
deactuated, and 0.0 VDC when actuated?
Replace the
Engine Logic
Board (RRP
9.3 on
page 6-89 ).
Replace the
Output Tray
Full Sensor
(RRP 6.6,
page 6-72 ).
Stack Height Sensor Checkout Procedure
Step Actions and Questions Yes No
1 1. Remove the tray from the feeder demonstrating a
problem.
2. Release the sensor from the feeder frame but do not
disconnect the plug from the sensor.
3. Measure the voltage on the pins as listed in the “Stack
Height Sensor Voltages” table.
Does the voltages on the bottom pin match the
voltage listed in the table?
Go to step 3. Go to step 2.
2 Check the wiring harness between the sensor and the
Feeder PWB.
Is the wiring in good condition?
Replace the
sensor (RRP
3.4 on
page 6-31 ).
Replace the
sensor wiring
harness.
(Item 14 in
PL 3.1 on
page 7-10 )
Output Tray Full Sensor Troubleshooting Procedure (cont'd.)
Step Actions and Questions Yes No