Lexmark E 450 Dn Service Manual

Diagnostics information2-25
4512-630
Black page
Note:  Incorrect laser exposure or incorrect charging of the photoconductor causes an all black page. Always 
verify the same results from a different print cartridge assembly and developer before proceeding.
Heavy background
Poor development or poorly charged toner particles cause excessive background. This is more noticeable as the 
toner cartridge nears end-of-life. FRU Action
Toner electrodes (not a 
FRU)Check the three rearward electrodes below the...

2-26Service Manual 4512-630
Partial blank image/white spots (no repeating pattern) 
Variation in image density horizontally across page 
Poor fusing of image 
FRU Action
Toner cartridge (not a 
FRU) Remove the toner cartridge assembly, and gently shake the assembly to evenly distribute 
the toner. 
Check to make sure that the laser light path is not blocked.
If toner cartridge is low, try a new one.
Paper (not a FRU) Make sure recommended media is being used.
Check the media settings in the printer...

Diagnostics information2-27
4512-630
Light print 
White or black lines or bands 
Toner on back of page 
FRU Action
Toner cartridge (not a 
FRU)Make sure the toner cartridge and PC Kit are installed correctly and that the toner cartridge 
is not low on toner. 
If the problem continues, install a new toner cartridge.
Recheck condition before replacing PC Kit, if necessary. 
Transfer roll 
LVPS/HVPS card Check the transfer roll for signs of toner buildup and contamination.
Inspect the HVPS contact (transfer...

2-28Service Manual 4512-630
Solving print quality problems
Note:  Refer to the print defects guide at the end of the manual for repeating defects.
Print quality problems
Problem Cause / action
Light or blurred 
characters. Light print
See “Light print” on page 2-27.
The toner cartridge may be getting low on toner: 
• Remove the toner cartridge and print cartridge assembly. 
• Shake it from side to side to redistribute the toner. 
• Reinstall it and recheck for condition.
• Make sure to use the...

Diagnostics information2-29
4512-630
Toner smears or rubs 
off the page. • Toner is not being fused to the media. Replace the fuser.
• Change the media texture setting in the driver. If special media is being used, such as 
card stock or labels, be sure to select the correct media type.
• Try a different kind of media. Media designed for copiers gives the best quality fusing. 
The print is getting 
light, but the printer 
has not indicated it is 
low on toner. • Toner is becoming low in the cartridge.
•...

2-30Service Manual 4512-630
The printer is on and 
indicates ready, but 
nothing prints. • Make sure the parallel or USB cable is not damaged and is firmly plugged into the 
connector on the back of the printer.
• Make sure the toner cartridge assembly is installed properly.
• Print the menu page found under Utilities.
- If a menu settings page cannot be printed, contact the next level of support.
- If a menu settings page can be printed, the problem is one of the following:
•Computer 
•Software program...

Diagnostics information2-31
4512-630
Printhead service check
Transfer roll service check 
Unexpected characters 
print or characters are 
missing.• Ensure correct printer driver is being used.
• Select hex trace mode to determine what the problem is.
• Restore factory defaults. 
• Make sure the parallel cable or USB cable is firmly plugged in at the back of the printer.
Jobs are not printing, 
and the error light is on 
solid. • The printer is waiting for an appropriate command.
• Make sure the print...

2-32Service Manual 4512-630 

Diagnostic aids3-1
  4512-630
3.  Diagnostic aids
This chapter explains the tests and procedures to identify printer failures and verify repairs have corrected the 
problem.
Accessing service menus
There are different test menus that can be accessed during POR to identify problems with the printer.
To run the printer diagnostic tests described in this chapter, you must put the printer in Diagnostic Mode.Diagnostics Mode 1. Turn off the printer.
2. Press and hold   and  .
3. Turn on the printer.
4....

3-2Service Manual 4512-630  
Diagnostics mode
Entering Diagnostics mode
1.Press and hold   and  .
2.Turn on the printer.
3.Release the buttons when Performing Self Test displays.
Available tests
The tests display on the operator panel in the order shown:
Diagnostics mode tests
REGISTRATIONSee “REGISTRATION” on page 3-4
Bottom Margin
To p  M a r g i n
Left Margin
Right Margin
Printhead See “Printhead assembly electronic adjustment” on page 3-6
Quick Test See “Quick Test” on page 3-12
PRINT TESTS
Tray 1...