Lexmark C 746 Service Manual

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interference. Have the network administrator verify that the device is using the correct SSID, and wireless 
security protocols. For more network troubleshooting information, consult the Lexmark Network Setup Guide.
Step Questions / actions Yes No
1If the device is physically connected to the 
network, verify that the ethernet cable is 
properly connected on both ends. 
Is the cable properly connected?Go to step 3.
If the network is wireless, 
got...

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15Is the printer on the same wireless network as 
the other devices?Go to step 17. Go to step 16.
16Assign the correct wireless network to the 
printer.
Did this fix the problem?Problem resolved. Go to step 17.
17Are the other devices on the wireless network 
communicating properly?Go to step 18. Contact the network 
administrator.
18Verify that the ISP wireless card cable is 
properly seated in their connectors. 
Is the wireless card seated correctly?Go to...

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Operator panel service check
One or more operator panel buttons fail
Operator panel display blank, five beeps, and LED is off
Service tip: The printer has detected a problem with the system board, the operator panel assembly cable (part 
of the top cover access assembly), or the operator panel assembly if POST does not complete. The printer emits 
five beeps, and then sticks in a continuous pattern until the printer is turned off.
Operator panel...

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NextStripes display, distorted display, and other display issues
Print quality service check
Note:  This symptom may require replacement of one or more CRUs (Customer Replaceable Units) designated 
as supplies or maintenance items, which are the responsibility of the customer. With the customers permission, 
you may need to install a developer (toner) cartridge or photoconductor unit.
2Check the operator panel assembly cable.
Is the cable damaged?Replace the top...

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Service tip: Before troubleshooting any print quality problems, do the following:
1.Print a menu settings page, and then check the life status of all supplies. Any supplies that are low should 
be replaced.
Note:  Be sure and keep the original menu page to restore the customers custom settings if needed.
2.On the menu page, make sure the following is set to the default level:
–Color Correction: Set to Auto.
–Print Resolution: Set to 1200 dpi (print...

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Print quality—blank page
3Check the high voltage contact from the 
HVPS to the transfer module.
Is a problem found?Replace the spring or the 
transfer contact assembly. Go to step 4.
4Reseat the JHVPS connector.
Does this fix the problem?Problem solved. Go to step 5.
5Replace the HVPS. See “High-voltage 
power supply (HVPS) removal” on 
page 4-115.
Does this fix the problem?Problem solved. Go to step 6.
6Clean the printhead.
Does this fix the...

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4Check 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 5.
5Turn 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. 
Print...

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Print quality—vertical banding
Replace the developer cartridge.
2Check 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 HPVS 
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...