Lexmark X644E Service Manual - Page 160

7002-xxx FRU 6 System board Action Replace the original system board with a new and not previously installed system board. If the problem remains, contact the next level of support. ADF paper length sensor service check-models X644e/X646e Note: There are two cables between the motor driver card and the paper length sensor. Check to make sure both cables are installed correctly. FRU 1 ADF paper length sensor (in ADF paper tray) 2 ADF paper length sensor Motor control card 3 ADF paper length sensor Action Enter the Diagnostics Menu (turn on MFP while holding 3 and 6), select SCANNER TESTS, and select Sensor Tests. Check the ADF paper length sensor for correct operation by putting a sheet of paper in the tray over the sensor. If the sensor does not operate properly, go to step 2. Turn the power off, and disconnect the cable to CN8, and measure the voltages at CN8 on the card. Measure the voltages shown in the table below: Paper length sensor-reflective type (normally closed) Connector CN8 (motor driver card) CN8-Pin 4 0 V dc CN8-Pin 5 +5 V dc CN8-Pin 6 +5 V dc Note: All voltages are approximate values. If incorrect, replace the motor driver card. If correct, go to step 3. Turn the power off and reconnect CN8 to the motor driver card. Measure the voltages in the table below: Interval sensor-reflective type (normally closed) Connector CN8 (motor driver card) Pin number Sensor closed Sensor open CN8-Pin 4 0 V dc 0 V dc CN8-Pin 5 CN8-Pin 6 +0.03 V dc +5.0 V dc +5.0 V dc +5.0 V dc Note: All voltages are approximate values. If the voltages are incorrect, replace the paper length sensor. If this does not fix the problem, replace the ADF paper tray assembly. If the problem persists, replace the complete ADF assembly. See "ADF complete assembly removal" on page 4-15. Note: Whenever the complete ADF assembly is replaced, it is necessary to perform scanner registration. See "Scanner registration" on page 4-4. 2-122 Service Manual