Lexmark C736 Service Manual

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5Check the high voltage contact from the 
HVPS to the photoconductor charge roll. 
Ensure the contact springs are properly 
mounted and that the charge roll contact 
spring is making good contact with the HVPS 
spring that runs through the left printer frame 
to view the proper mounting and for removal 
procedures.
Are the spring(s) defective?Replace the transfer 
contact assembly.Go to step 6.
6Turn off the printer and check the continuity of 
the...

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Print quality—blurred or fuzzy print
Blurred or fuzzy print is usually caused by a problem in the EP drive assembly or in the transfer module. Check 
the EP drive assembly and transfer module for correct operation.
Blurred print can also be caused by incorrect feeding from one of the input paper sources, paper trays, or duplex 
paper path.
Check the high voltage spring contacts to ensure they are not bent, corroded, or damaged. Replace as 
necessary.
Print...

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Print quality—random marks
Service tip: The primary cause of random marks is due to loose material moving around inside the printer and 
attaching to the photoconductor unit, developer roll, or transfer module.
Print quality—residual image
Service tip: Install a new print cartridge if available before doing this service check. Residual image can be 
caused by the photoconductor, cleaning blade, and other parts inside the print cartridge.  Step...

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Print quality—solid color page
Service tip: A solid color page is generally caused by a problem in the high voltage system or an incorrect high 
voltage in the printing process resulting in toner development on the entire photoconductor drum.
Step Questions / actions Yes No
1Replace the photoconductor unit for the color 
in question.
Does this fix the problem?Problem solved. Go to step 2.
2Check the high voltage contact from the 
HVPS to the photoconductor...

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NextPrint quality—vertical banding
Replace the developer cartridge.
Print quality—white gapping
4Replace the HVPS. See “High-voltage 
power supply (HVPS) removal” on 
page 4-108. 
Did this solve the problem?Problem solved. Replace the system board. 
See “System board 
removal” on page 4-153. 
Step Questions / actions Yes No
11. Open the front cover. 
2. Remove the toner cartridge base on the 
color of the print quality defect.
3. Inspect the cartridge...

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NextTray linking service check
Tray linking is useful for large print jobs or multiple copies. When one linked tray is empty, paper feeds from the 
next linked tray. When the Paper size and Paper Type settings are the same for any trays, the trays are 
automatically linked.
91. Reseat the HVPS card. 
2. Make sure the contacts is properly aligned 
with the HVPS.
Does this fix the problem?Problem resolved. Replace the HVPS. See 
“High-voltage power 
supply (HVPS)...

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3.  Diagnostic aids
This chapter explains the tests and procedures to identify printer failures and verify repairs have corrected the 
problem.
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 Diagnostics mode.Diagnostics menu 1. Turn off the printer.
2. Press and hold   and  .
3. Turn on the printer.
4. Release the...

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Diagnostics menu
Note:  Tray 2 refers to the 550-sheet tray located in the 550-sheet option assembly.
Diagnostics menu structure
When the Diagnostics mode is entered, each Diagnostics main menu item displays on the operator panel. When 
a diagnostic test is selected from the main menu, a sub menu displays and each individual test displays in the 
order shown. Any options that are referred to in the menus are displayed when the option is installed.
Available...

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PRINT TESTS
Tray 1 See “Input source tests” on page 3-10.
Tray 2 (if installed)
Tray 3 (if installed)
Tray 4 (if installed)
Tray 5 (if installed)
Multi-Purpose Feeder
Prt Quality Pgs See “Print quality test pages (Prt Quality Pgs)” on page 3-11.
HARDWARE TESTS
Panel Test See “Panel Test” on page 3-12.
Button Test See “Button Test” on page 3-12.
DRAM Test See “DRAM Test” on page 3-12.
Serial 1 Wrap (if a serial port is 
available in the PCI slot 1)See...

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DEVICE TESTS (if hard disk or flash is installed)
Quick Disk Test See “Quick Disk Test” on page 3-18.
Disk Test/Clean See “Disk Test/Clean” on page 3-19.
Flash Test See “Flash Test” on page 3-19.
PRINTER SETUP
Defaults See “Defaults” on page 3-20.
PAGE COUNTS See “Page Counts” on page 3-20.
Prt Color Pg Count
Prt Mono Pg Count
Perm Page Count
Serial Number See “Serial Number” on page 3-20.
Engine Setting 1 through 4 See “Engine Setting 1 through 4” on page...