Lexmark 13P0150 - C 750dtn Color Laser Printer, Service Manual

Page: 95 / 262

Diagnostic Information
2-75
5060-XXX
Uneven printing
If all colors have uneven print, replace the ITU assembly.
Note: The uneven print may appear as spots or streaks that are different on each page.
The most likely cause for this type of problem is damage to the ITU belt in the ITU
assembly. Replace the
“ITU Assembly” on page 4-40 .
If only one color is missing or printing uneven, go to step 1.
2
HV Contact Block Assembly Check, Doctor Blade or TAR
Contact - Check for a stuck TAR contact pin in the HV
Contact Block Assembly of the colors with the problem.
Look at figure 1 for pin locations.
Is the TAR contact pin stuck or operating smoothly for the
colors with the problem? Go to Step 3 Repair the HV
Block Contact
for the faulty
color
3
Doctor Blade Contact - Check to make sure the Doctor
Blade Cable is connected to the Doctor Blade terminal on
the Developer HVPS.
Is the cable connected correctly? Go to Step 4 Connect the
cable
correctly.
Replace the
cable if it is
broken or
damaged.
4
Doctor Blade Contact Pin in HV Contact Block Assembly
Check to make sure the Doctor Blade Contact Pin in the HV
Contact Block assembly is not stuck and is operating
smoothly. Look at figure 1 for pin location.
Is the Doctor Blade contact pin stuck operating smoothly? Go to Step 5 Repair the HV
Block Contact
for the faulty
color.
5
Continuity Check - High Voltage Contact Assembly - Check
continuity from the Developer HVPS Contact Spring to the
Charge Roll Pin in the contact assembly.
Is there continuity? Go to Step 6 Repair the
High Voltage
Contact
Assembly as
necessary
6
Cartridge HV contact Assembly Developer Pin Springs
Check the developer pin springs for the cartridge that is
having a problem to make sure they are no bent or
damaged.
Are the springs bent or damaged? Replace the
damaged
Developer
Spring Replace the
“HVPS
Developer
Board” on
page 4-36
Step Action and Questions Yes No
1
Print Cartridge - Check to make sure the cartridge is seated
properly and that all packing material has been removed
from the cartridge.
Has all packing material been removed and the cartridge is
seated correctly? Problem
Solved Go to Step 2
Step Action and Questions Yes No