Lexmark C 746 Service Manual
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Diagnostic information2-115 5026 Go Back Previous Next 925.02, 925.04, 925.06—Cartridge cooling fan error service check 31. Disconnect the cable in connector JFAN1, and install a new fan. 2. Turn the multifunction printer off, and turn the MFP on (perform a POR). Note: After installing the new fan, a print test is required to verify operation. Print one page every 30 seconds for 20 minutes to test the highest fan speed. Do not test unless the fan is installed in the machine. Did the error clear?Replace the cooling fan. See “Cooling fan removal” on page 4-85. Replace the system board. See “System board removal” on page 4-155. Step Questions / actions Yes No 1Turn the printer off, and remove the rear frame cover. See “Rear frame cover removal” on page 4-47. Check the cable in connector JBLW1 for proper connection to the system board, for pinch points, and any other damage to the cable or connector, and reseat the cable. Did the error clear?Problem resolved. Go to step 2. 2Measure the continuity across all of the fuses on the system board. Are any of the fuses blown?Replace the system board. See “System board removal” on page 4-155. Go to step 3. 31. Replace the cartridge cooling fan. See “Cartridge cooling fan removal” on page 4-66. 2. Turn the multifunction printer off, and turn the MFP on (perform a POR). Note: After installing the new fan, a print test is required to verify operation. Print one page every 30 seconds for 20 minutes to test the highest fan speed. Do not test unless the fan is installed in the machine. Did the error clear?Problem resolved. Replace the system board. See “System board removal” on page 4-155. Step Questions / actions Yes No
2-116Service Manual 5026 Go Back Previous Next 945.xx, 947.xx—Transfer roll error service check Step Questions / actions Yes No 11. Replace the transfer module. See “Transfer module removal” on page 4-171. 2. POR the printer. Note: Print 5 pages one at a time to check operation. Did the error clear?Problem resolved. Replace the original transfer module. Go to step 2. 2Turn the printer off, and then remove the rear frame cover. See “Rear frame cover removal” on page 4-47. Check the cable in connector JHVPS1 for proper connection to the system board, the cable for pinch points, and the cable or connector for any other damage. Is the cable damaged?Replace the HVPS cable. See “High-voltage power supply (HVPS) cable removal” on page 4-117. Go to step 2. 3Disconnect JHVPS1 from system board and HVPS. Check for the following continuity.Go to step 3. Replace the HVPS cable. See “High-voltage power supply (HVPS) cable removal” on page 4-117. Is continuity present? Pin 24 Pin 23 Pin 1 Pin 2Pin 2Pin 1Pin 23 Pin 24 JHVPS1 cable to: Error code HVPS System board Pin 19 Pin 19 945.01, 946.01, 947.01 Pin 20 Pin 20 Pin 15 Pin 15 945.02, 946.02, 947.02 Pin 16 Pin 16 Pin 17 Pin 17 945.03, 946.03, 947.03 Pin 18 Pin 18 Pin 23 Pin 23 945.04, 946.04, 947.04 Pin 24 Pin 24
Diagnostic information2-117 5026 Go Back Previous Next 4Remove the HVPS. See “High-voltage power supply (HVPS) removal” on page 4-115. Check for continuity between the contacts (yellow1 and yellow2, cyan1 and cyan2, magenta1 and magenta2, or black1 and black2) on the transfer contact assembly. Go to step 4. Replace the transfer contact assembly. Is continuity present? 4 Replace the HVPS. See “High-voltage power supply (HVPS) removal” on page 4-115. Does the error clear?Problem resolved. Replace the system board. See “System board removal” on page 4-155. Step Questions / actions Yes No yellow2 cyan2 magenta2 black2yellow1 cyan1 magenta1 black1
2-118Service Manual 5026 Go Back Previous Next 950.00–950.29—EPROM mismatch failure Warning:When replacing any one of the following components: •System board •Operator assembly card or top access cover assembly Replace only one component at a time or the printer will be rendered inoperable. Replace the required component, bring the printer up in Diagnostic menu (see “Diagnostics menu” on page 3-2), and verify that the problem is fixed before performing a POR. This error code indicates a mismatch between the operator panel assembly and the system board. Step Questions / actions Yes No 1Has the operator panel assembly been replaced recently?Replace the operator panel assembly with a new, and not previously installed, operator panel assembly, See “Operator panel assembly removal (C746)” on page 4-34 or “Operator panel assembly removal (C748)” on page 4-37. Go to step 2. 2Has the top access cover assembly been replaced recently?Replace the top access cover assembly with a new, and not previously installed, operator panel assembly. See “Top access cover assembly removal” on page 4-54. Go to step 3. 3Has the system board been replaced recently?Replace the system board with a new, and not previously installed, system board. See “System board removal” on page 4-155. Go to step 4. 4Turn the printer power off for ten or more seconds. Then turn the printer back on (POR the printer). Is the error gone, and can the printer print?Problem resolved. Go to step 5. 5Clear the NVRAM of the printer: 1. Turn the printer power off. 2. With the printer off, press and hold buttons 2, 6, 7, and 8. 3. Turn the printer power on. 4. When the printer screen displays Restoring Factory Defaults, release the buttons. Note: If the printer locks up on the Restoring Factory Defaults, wait two minutes, and then turn the printer power off. After ten seconds or more, turn the printer power back on without holding down any buttons. Is the error message still displayed?Go to step 6. Problem resolved.
Diagnostic information2-119 5026 Go Back Previous Next956.xx—System board failure service check 6Replace the operator panel assembly. See “Operator panel assembly removal (C746)” on page 4-34 or “Operator panel assembly removal (C748)” on page 4-37. Is the error message still displayed?Replace the system board. See “System board removal” on page 4-155. Problem resolved. Step Questions / actions Yes No 1Turn the printer off, and remove the rear frame cover. See “Rear frame cover removal” on page 4-47. Check the cable in connector J49 for proper connection to the system board. Is the cable seated correctly?Replace the system board. See “System board removal” on page 4-155.Reseat the cable. Step Questions / actions Yes No A
2-120Service Manual 5026 Go Back Previous Next 5 V interlock switch service check Step Questions / actions Yes No 1Is the +5 V interlock switch damaged? Replace the 5 V interlock switch. See “5 V interlock switch cable removal” on page 4-61.Go to step 2. 2Turn the printer off, and remove the rear frame cover. See “Rear frame cover removal” on page 4-47. Check the cable in connector JINT1 for proper connection to the system board, for pinch points, and for any other damage to the cable or connector. Is the cable damaged?Replace the 5 V interlock switch. See “5 V interlock switch cable removal” on page 4-61.Go to step 3. 31. Disconnect the cable in connector JINT1. 2. Connect the new 5 V interlock switch to JINT1. 3. Bring the printer up in Diagnostics Menu (turn off the printer, press and hold buttons 3 and 6, then turn on the printer). 4. Activate the 5 V interlock switch. Does the display change from Close Front Door to the Diagnostic Menu?Replace the 5 V interlock switch. See “5 V interlock switch cable removal” on page 4-61.Replace the system board. See “System board removal” on page 4-155. A
Diagnostic information2-121 5026 Go Back Previous Next 24 V interlock switch service check Step Questions / actions Yes No 1Is the 24 V interlock switch damaged? Replace the 24 V interlock switch. See “24 V interlock switch removal” on page 4-63.Go to step 2. 2Turn the printer off, and remove the rear frame cover. See “Rear frame cover removal” on page 4-47. Check the cable in connector JCVR1 for proper connection to the system board, for pinch points, and for any other damage to the cable or connector. Is the cable damaged?Replace the 24 V interlock switch. See “24 V interlock switch removal” on page 4-63.Go to step 3. 31. Disconnect the cable in connector JCVR1. 2. Connect the new 24 V interlock switch to the connector JCVR1. 3. Bring the printer up in Diagnostics Menu (turn off the printer, press and hold buttons 3 and 6, then turn on the printer). 4. Activate the new 24 V interlock switch. Does the display change from Close Front Door to the Diagnostic Menu.Replace the 24 V interlock switch. See “24 V interlock switch removal” on page 4-63.Replace the system board. See “System board removal” on page 4-155.
2-122Service Manual 5026 Go Back Previous Next Bubble sensor service check Step Questions / actions Yes No 1Is the bubble sensor flag damaged? Replace the fuser. See “Fuser removal” on page 4-110.Go to step 2. 2Remove the rear frame cover. See “Rear frame cover removal” on page 4-47. Check the fuser DC cable in connector JFUSER1 for proper connection to the system board, pinch points, and any other damage to the cable or connector. Is the cable damaged?Replace the fuser DC cable. See “Fuser DC cable removal” on page 4-113. Note: Make sure to verify if the new cable is working properly first. Route the cables properly only when you have verified that the cables are working properly.Go to step 3. 3Place a voltmeter between the fuser DC autoconnect, pin 3 and ground (pin 6). Does the voltage meter read +5 V dc?Go to step 5. Go to step 4. 4Place a voltmeter between FUSER1 pin 3 and ground (pin 6). Does the meter read +5 V dc?Replace the system board. See “System board removal” on page 4-155.Go to step 5. Pin 6 (ground) Pin 3
Diagnostic information2-123 5026 Go Back Previous Next 51. Replace the fuser. 2. Bring the printer up in Diagnostics Menu (turn off the printer, press and hold buttons 3 and 6, then turn on the printer). 3. Navigate to SENSOR TESTS > Dynamic Sensors > Bubble. 4. Open the front door. 5. Activate the bubble sensor. Did the bubble sensor change from Open to Closed?Problem resolved. Replace the system board. See “System board removal” on page 4-155. Step Questions / actions Yes No
2-124Service Manual 5026 Go Back Previous Next Dead printer service check A dead printer is a condition where the display is blank, the LED on the operator panel is off, no fans turn, no motors turn, and the fuser lamp does not come on. If a 550-sheet option assembly is installed, remove the option and check the base printer for correct operation. If the base printer operates correctly, replace the 550-sheet option assembly. Warning:Observe all necessary ESD precautions when removing and handling the system board or any installed option cards or assemblies. See “Handling ESD-sensitive parts” on page 4-2. Remove any input and output paper handling options from the printer. Networking service check Note: Before starting this service check, print out the network setup page. This page is found under Menu— Reports—Network Settings. Consult the network administrator to verify that the physical and wireless network settings displayed on the network settings page for the device are properly configured. If a wireless network is used, verify that the printer is in range of the host computer or wireless access point, and there is no electronic Step Questions / actions Yes No 1Check the AC line voltage. Is the line voltage correct?Go to step 2. Inform the customer. 2Is the AC line cord damaged? Replace the line cord. Go to step 3. 3Check the system board for +5 V dc between JLVPS2 pin 1 and ground. Is the voltage correct?Replace the system board. See “System board removal” on page 4-155. Go to step 4. 4Is the JLVPS2 cable correctly installed at JLVPS2 on the system board?Go to step 5. Reseat the JLVPS2 cable. 5Turn the printer off. Disconnect the JLVPS2 cable from the system board. Turn the printer on, and then measure the voltage between the JLVPS2 cable pin 1 and the JLVPS2 pin 14 (black wire). Does this measure approximately +5 V dc?Go to step 6. Replace the LVPS. See “Low-voltage power supply (LVPS) removal” on page 4-119. 61. Turn the printer off. 2. Disconnect the cables in J5, JCARTS1, JCARTS2, JDVR1, JFDPCK1, JFUSER1, JINT1, JOPT1, and JTLBT1. 3. Connect the JLVPS2 cable to the system board. 4. POR the printer. Does the printer still appear dead?Contact your next level of support.Go to step 7. 71. Connect one cable at a time, and POR the printer. 2. Is the printer dead?The part connected to that cable is faulty. Replace the failing part.Connect another cable and continue with this step. CAUTION When you see this symbol, there is a danger from hazardous voltage in the area of the product where you are working. Unplug the product before you begin, or use caution if the product must receive power in order to perform the task.