Lexmark C 746 Service Manual
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Diagnostic information2-125 5026 Go Back Previous Next 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 to step 3.Go to step 2. 2Connect the ethernet cable. Did this fix the problem?Problem resolved Go to step 3. 3Check the printer’s online status under Printers and Faxes on the host computer. Delete all print jobs in the print queue. Is the printer online and in a Ready state.Go to step 5. Go to step 4. 4Change the printer status to online. Did this fix the issue?Problem resolved. Go to step 5. 5Does the IP address displayed on the network settings page match the IP address in the port of the drivers using the printer?Go to step 10. Go to step 6. 6Does the LAN use DHCP? Note: A printer should use a static IP address on a network.Go to step 7. Go to step 9. 7Are the first two segments if the IP address 169.254?Go to step 8. Go to step 9 8POR the printer. Is the problem resolvedProblem resolved Go to step 10. 9Reset the address on the printer to match the IP address on the driver. Did this resolve the issue?Problem fixed. Go to step 10. 10Have the network admin verify that the printer and PC’s IP address have identical subnet addresses. Are the subnet addresses the same?Go to step 12. Go to step 11. 11Using the subnet address supplied by the network admin, assign a unique IP address to the printer. Do not assign an address that is already in use on the network. Note: The printer IP address should match the IP address on the printer driver. Did this fix the problem?Problem resolved. Go to step 12. 12Is the device physically connected (ethernet cable) to the network?Go to step 13. Go to step15. 13Try using a different ethernet cable. Did this remedy the situation?Problem resolved. Go to step 14. 14Have the network administrator check the network drop for activity. Is the drop functioning properly?Replace the system board. See “System board removal” on page 4-155.Contact the network administrator.
2-126Service Manual 5026 Go Back Previous Next 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 step 20. Go to step 19. 19Properly reseat the ISP cables. Did this fix the problem?Problem resolved. Go to step 20. 20Replace the ISP wireless card. See Installing an Internal Solutions Port (ISP). Did this fix the problem?Problem resolved. Replace the system board. See “System board removal” on page 4-155. Step Questions / actions Yes No
Diagnostic information2-127 5026 Go Back Previous Next 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 display blank, five beeps, LED on 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. Step Questions / actions Yes No 1Run the Button Test. See“Button Test” on page 3-14 in Diagnostics mode. Did any of the buttons fail the test?Replace the operator panel assembly. See “Operator panel assembly removal (C746)” on page 4-34. Go to step 2. 2Disconnect the operator panel assembly cable from JOPP1 on the system board, and then measure the voltage on pin 6 and ground. Does the voltage measure approximately +3.3 V dc?Replace the operator panel assembly. See “Operator panel assembly removal (C746)” on page 4-34. If this does not fix the problem, replace the top cover access assembly. See “Top access cover assembly removal” on page 4-54. Replace the system board. See “System board removal” on page 4-155. Step Questions / actions Yes No 1Is the operator panel assembly cable properly installed at system board JOPP1 and at the operator panel assembly?Go to step 2. Reinstall the cable. 2Measure the voltage between JOPP1 pin 2 and ground on the system board. Is the voltage approximately +5 V dc?Go to step 3. Replace the system board. See “System board removal” on page 4-155. 3Check continuity of the operator panel assembly cable. Is there continuity?Replace the operator panel assembly. See “Operator panel assembly removal (C746)” on page 4-34. Replace the top cover access assembly. See “Top access cover assembly removal” on page 4-54. Step Questions / actions Yes No 1Check for ground between JOPP1 pin 4 and ground. Is the voltage approximately 0 V dc?Replace the operator panel assembly. See “Operator panel assembly removal (C746)” on page 4-34. Go to step 2.
2-128Service Manual 5026 Go Back Previous 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 cover access assembly. See “Top access cover assembly removal” on page 4-54. Replace the system board. See “System board removal” on page 4-155. Step Questions / actions Yes No 11. Turn off the printer. 2. Open the rear cover. 3. Reseat the operator panel cable (J2) on the system board. 4. Check the J2 connector on the system board for any damage. Is the connector damaged?Replace the system board. See “System board removal” on page 4-155.Go to step 2. 21. Turn off the printer. 2. Disconnect the J2 operator panel cable. 3. Connect a new top access cover assembly from outside of the machine for verification. Does the problem persist?Return to the Old Top access cover assembly, then go to step 6.Return to the Old Top access cover assembly, then go to step 3. 31. Open the top access cover assembly, Refer to “Top access cover assembly removal” on page 4-54. 2. Reseat the operator panel cable on both ends. 3. Check for any damage on the cable. Is the cable damaged? Replace operator panel cable. See “Operator panel cable removal” on page 4-132.Go to step 4. 4• For C746x: Replace the 2.3 inch operator panel assembly with card. See “Operator panel assembly removal (C746)” on page 4-34. • For C748x: Replace the UICC card. See “Operator panel assembly removal (C748)” on page 4-37. Does the problem persist?• For C746x: Return the old 2.3 inch operator panel assembly with card, then go to step 6. • For C748x: Return the old UICC card, then go to step 5.Problem resolved. 5Replace the LCD panel. Does the problem persist?Go to step 6. Problem resolved. 6Replace the Operator panel cable. Does the problem persist?For dead display. Go to Dead printer service check. Replace the system board. See “System board removal” on page 4-155.Problem resolved. Step Questions / actions Yes No
Diagnostic information2-129 5026 Go Back Previous Next 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 quality problems should be checked at different resolution settings). –Toner Darkness: Set to 4 (default). –Color Saver: Set to OFF. –RGB Brightness, RGB Contrast, RGB Saturation: Set to 0. –Color Balance: Select Reset Defaults to zero out all colors. –Check the paper type, texture and weight settings against what is loaded in the printer. Once the printer has been restored to its default levels, do the following: 3.Inspect the transfer module for damage. Replace if damaged. 4.Inspect the photoconductor units and toner cartridges for damage. Replace if damaged. 5.If paper other than 20 lb plain letter/A4 paper is being used, load 20 lb plain letter/A4 and print the Print Quality pages to see if the problem remains. 6.Use Tray 1 to test print quality problems. 7.Print the Print Quality Pages, and then look for variations in the print from what is expected. An incorrect printer driver for the installed software can cause problems. Incorrect characters could print, and the copy may not fit the page correctly. Measure all voltages from the connector to the printer ground. Print quality—background Service tip: Some background problems can be caused by rough papers, non-Lexmark toner cartridges or if the media texture is set to the rough setting. Some slick or coated papers may also cause background problems. Some problems occur with printers that run a large amount of graphics in a humid environment. Step Questions / actions Yes No 1Read the current status of the photoconductor unit from the customer menus. To view the status of the photoconductor units: 1. In Ready mode, select Admin Menu. 2. Select Reports. 3. Select Device Statistics. Ask the customer if the photoconductor unit has been recently replaced. It is possible the photoconductor value was not reset and the photoconductor unit is past end of life. If the PC unit was recently replaced, reset the value. If the PC unit was not replaced, replace the PC unit. Has the photoconductor unit been recently replaced?Reset the value. To reset this value: 1. In Ready mode, select Admin Menu. 2. Select Supplies Menu. 3. Select Replace Supply. 4. Select the PC color unit you want to change 5. Select Yes. If this does not fix the problem, go to step 2.Go to step 2. 2Replace the PC unit. See “Photoconductor unit removal” on page 4-142. Does this fix the problem?Problem solved. Go to step 3.
2-130Service Manual 5026 Go Back Previous Next 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 problem?Problem solved. Replace the printhead. See “Printhead removal, installation, and adjustment” on page 4-145. Step Questions / actions Yes No 1Is all the packing material for the photoconductor unit in question removed?Go to step 2. Remove the packing material. 2Replace the photoconductor unit for the color in question. Does this fix the problem?Problem solved. Go to step 3. 31. Enter the Diagnostics mode (turn off the printer, press and hold buttons 3 and 6, then turn on the printer). 2. Perform the appropriate cartridge drive motor test for the missing color. See “General motor tests procedures” on page 3-10. Did the motor run?Go to step 4. Replace the EP drive assembly. See “Electrophotographic (EP) drive assembly removal” on page 4-90. Step Questions / actions Yes No Transfer belt high voltage path (typical 4X)
Diagnostic information2-131 5026 Go Back Previous Next 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 HVPS cable.Go to step 6. Replace the cable assembly. Is there continuity? 6Replace the HVPS. See “High-voltage power supply (HVPS) removal” on page 4-115. Did this fix the problem?Problem solved. Go to step 7. 7Replace the printhead. See “Printhead removal, installation, and adjustment” on page 4-145. Did this fix the problem?Problem solved. Replace the system board. See “System board removal” on page 4-155. Step Questions / actions Yes No High voltage contact pathHigh voltage power supply Pin 24 Pin 23 Pin 1 Pin 2Pin 2Pin 1Pin 23 Pin 24
2-132Service Manual 5026 Go Back Previous Next 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 quality—half-color page A photoconductor unit is not properly seated. Reset the specific photoconductor unit. Print quality—horizontal banding Print quality—horizontal line The photoconductor unit is defective. Replace the photoconductor unit. Print quality—insufficient fusing Print quality—missing image at edge Reseat the developer cartridge. Print quality—mottle (2–5mm speckles) Keep running prints through, and the problem normally clears up. If the problem persists, replace the developer cartridge. Print quality—narrow vertical line Step Questions / actions Yes No 1Measure the distance between repeating bands. Is the distance between bands either 27 or 36mm?Replace the print cartridge. Replace the photoconductor unit. See “Photoconductor unit removal” on page 4-142. Step Questions / actions Yes No 1Is the fuser properly installed? Go to step 2. Install the fuser properly. 2Replace the fuser. See “Fuser removal” on page 4-110. Does this fix the problem?Problem solved. Replace the LVPS. see “Low-voltage power supply (LVPS) removal” on page 4-119. Step Questions / actions Yes No 1Replace the photoconductor unit. See “Photoconductor unit removal” on page 4-142. Problem solved. Replace the print cartridge.
Diagnostic information2-133 5026 Go Back Previous Next 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 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 1Is there any loose or foreign material on the photoconductor unit?Replace the photoconductor unit. See “Photoconductor unit removal” on page 4-142.Go to step 2. 2Is there any loose or foreign material on the cartridge roll?Replace the print cartridge. Go to step 3. 3Is there any loose or foreign material on the transfer module?Replace the transfer module. See “Transfer module removal” on page 4-171.Contact your next level of support. Step Questions / actions Yes No 1Is there any toner contamination on the fuser assembly?Replace the fuser. See “Fuser removal” on page 4-110.Contact your next level of support. 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.
2-134Service Manual 5026 Go Back Previous Next 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 3. 3Turn the printer off, and then check the continuity of the HVPS cable.Go to step 4. Replace the cable assembly. Is there continuity? 4Replace the HVPS. See “High-voltage power supply (HVPS) removal” on page 4-115. Did this solve the problem?Problem solved. Replace the system board. See “System board removal” on page 4-155. Step Questions / actions Yes No Note: Printer is shown with components removed for clarity High volt power supply High volt contact path Pin 24 Pin 23 Pin 1 Pin 2Pin 2Pin 1Pin 23 Pin 24