Toner Sensor Failure - Xerox 4400DT - Phaser B/W Laser Printer Service Manual

Toner Sensor Failure

Low Toner is not displayed when the Print Cartridge appears to be empty.
Low Toner Sensor Failure Troubleshooting Procedure
Step Actions and Questions
1 Print a Test Print. Inspect the print quality.
Is the print light?
2 1. Replace the Print Cartridge (PL 8.1 on
2. Run 5 test prints (Configuration Page or Demo Page)
and inspect the print quality following the guidelines
in Image-Quality Checkout Procedures
page 3-41.
Does the print quality appear acceptable?
3 1. Enter Service Diagnostics and select Sensor Tests.
2. Scroll to Toner Sensor and press OK.
3. Open the Front Cover and cheat the Front Cover
Interlock.
4. Remove and replace the Print Cartridge two or three
times.
Does the message on the Front Panel display
alternate between Toner Normal and Toner Low
as you remove and replace the Print Cartridge?
4 1. Switch the printer power OFF.
2. Remove the Front Cover (RRP 1.6 on
the Left Front Cover (RRP 1.7 on
3. Cheat the Front Cover Interlock.
4. Switch the printer power ON.
5. On the connector PWB, check the voltage between
P/J42 pin 4 and frame ground.
Is the voltage 0.0 VDC with the print cartridge
installed, and +3.3 VDC with the print cartridge
removed?
5 Check the voltage between P/J42 pin 3 and pin 1.
Is the voltage +24 VDC?
6 On the Connector PWB, check the voltage between
P/J231 pin 11 and pin 12.
Is the voltage +24 VDC?
7 On the connector PWB, check the voltage between
P/J231 pin 9 and frame ground.
Is the voltage 0.0 VDC with the print cartridge
installed, and +3.3 VDC with the print cartridge
removed.
3-8
page 7-20).
on
page 6-11) and
page 6-12).
Phaser 4400 Laser Printer Service Manual
Yes No
Go to step 2. Return to
Service
Flowchart
page 2-2.
Go to step 3. Go to
(Undertoned)
Prints
page 3-54.
Replace the Go to step 4.
Engine Logic
Board (RRP
9.3 on
page 6-89).
Go to step 7. Go to step 5.
Replace the Go to step 6.
Toner Sensor
(RRP 5.2 on
page 6-59).
Replace the Go to step 8.
Connector
PWB (RRP
9.7 on
page 6-94).
Go to step 8. Replace the
Connector
PWB (RRP
9.7 on
page
on
Light
on
6-94).