Printhead Service Check; Transfer Roll Service Check - Lexmark E450DN - E 450dn B/W Laser Printer Service Manual

Print quality problems (Continued)
Problem
Unexpected characters
print or characters are
missing.
Jobs are not printing,
and the error light is on
solid.
While in PostScript 3
emulation, the printer
is flushing data
(Ready/Data and Error
lights are blinking).

Printhead service check

FRU
Printhead
Note: New printhead
must be aligned. See
"Printhead assembly
electronic
adjustment" on
page 3-6.

Transfer roll service check

FRU
Transfer roll
Cause / action
• 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.
• The printer is waiting for an appropriate command.
• Make sure the print cartridge assembly is installed properly.
• Make sure the printer front cover is closed.
• Ensure the correct PostScript driver is being used.
• The printer doesn't have enough memory to print the job. Install more memory.
Action
Turn the printer off.
Disconnect the printhead cables from J8 and J15 on the controller card.
Turn the printer on with the front door closed.
On the controller card, verify +5 V dc on pin 10 at J8 and +5 V dc on pins 1 and 2 at J15.
Verify grounds on pins 2, 4, and 7 at J8 and on pin 4 at J15.
• If voltages or grounds are incorrect, check the controller card. See
service check" on page 2-17
• If voltages are correct, replace the printhead (comes with cables).
Action
Note: Do not touch the transfer roll except at its ends. Place a sheet of paper over the roll to
prevent damage from finger oils or hand lotion.
Check the springs in the left and right transfer roll bearings. The bearing assemblies should
support the transfer roll, applying evenly distributed forces to the PC drum.
Note: Do not try to move the left spring.
Replace the transfer roll assembly if the springs or bearings show signs of damage or
fatigue.
Inspect the transfer roll for signs of wear, damage or contamination.
Replace as necessary.
for more information.
4512-630
"Controller card
2-31
Diagnostics information