Reflective Sensor Procedure - Xerox 7750DXF - Phaser Color Laser Printer Service Manual

Reflective Sensor Procedure

Troubleshooting References
Applicable Parts
Reflective Sensor
Engine Control Board
Refer to the figure below during this procedure..
PWB
PL
CONTROL
LOGIC
Troubleshooting Procedure
Step Actions and Questions
1 1. Enter service diagnostics and run the
Reflective Sensor test.
2. Does the sensor change state from L
to H when blocked?
2 1. Measure Pin 2 to ground.
2. Is there +5 VDC?
3
1. Check the wire between Pin 2 and
engine control board Pin 8 for an open
circuit or poor contact.
2. Is the wiring OK?
4
1. Is there +5 VDC between sensor Pin 1
and Pin 3?
5 1. Is there +5 VDC between engine
control board Pin 4 and Pin 5?
6 1. Check the wiring to Pin 4 and sensor
Pin 1 and Pin 5 to sensor Pin 3 for an
open or poor circuit.
2. Is the wiring OK?
Error Messages and Codes
PWB
PL
4
DC ROM
5
+5VDC
8
Wiring and Plug/Jack Map References
DOUBLE
PLUG
DC ROM
+5VDC
7
Yes
Replace the
sensor.
Go to step 4.
Replace the
board.
Replace the
sensor.
Go to step 6.
Replace the
engine control
board.
SENSOR
PL
1
3
6
No
Go to step 2
Go to step 3.
Repair or replace
the wiring
harness.
Go to step 5.
Replace the
engine control
board.
Replace the
wiring harness.
J121
2
7750-343
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