Lexmark C752 Service Manual page 112

5060-2XX
Displayed with no media in MPF
A 250 Paper Jam indicates that the MPF tried to feed a sheet of media from the MPF tray. A 250 Paper Jam may
occur when there is no paper in the MPF, MPF is selected as the paper source, or the MPF sensor is
malfunctioning. If media is in the MPF it may feed normally with no 250 Paper Jam even though the sensor is
malfunctioning.
Step Action and questions
1 Enter the Diagnostics Menu. Select Input Tray Tests,
Sensor Test, and Multipurpose Feeder. Manually
actuate the MPF sensor by moving the paper flag in
the MPF.
Does the test pass?
2 Make sure that the MPF sensor cable from the system
board is correctly installed at J21 on the system board.
Is the cable correctly installed?
3 Check the cable connection between the MPF sensor
cable and the sensor. Check that the sensor is
snapped into the bracket.
Is the connection good between the two cables?
4 Disconnect the sensor cable from J21 on the system
board.
Measure the following voltages on J21, being careful
not to short any adjacent pins in the connector. All
voltages are approximate values.
Connector pin Voltage
J21-11
J21-12
J21-13
J21-14
Are the voltages correct?
5 Check continuity of the sensor cable that is between
the system board and MPF assembly.
Is there continuity?
2-78
Service Manual
0 V dc
+5 V dc
+5 V dc
+5 V dc
Yes No
Replace the MPF Go to step 2
assembly.
Go to step 3 Install the cable
correctly
Go to step 4 Install the cable
correctly
Go to step 5 Replace the
"System board"
on page 4-67
Replace the Replace the
sensor assembly sensor cable
assembly