Waste Cartridge Full Detection Sensor Failure, Code 78 - Xerox 7750DXF - Phaser Color Laser Printer Service Manual

Waste Cartridge Full Detection Sensor Failure, Code 78

Troubleshooting References
Applicable Parts
Waste Cartridge
Waste Cartridge Full Sensor
Engine Control Board
Troubleshooting Procedure
Step Actions and Questions
1 1. Remove the waste cartridge sensor
holder without disconnecting the
harnesses.
2. Measure the voltage between the
yellow wire on the waste cartridge full
sensor and frame ground, alternately
interrupting the sensor.
3. Does the voltage toggle between +5
and 0 VDC?
2 1. Measure the voltage between the gray
wire and frame ground.
2. Does the voltage measure +5 VDC?
3
1. Remove the rear cover and rear shield.
2. Measure the voltage at J407B-17 on
the engine control board.
3. Does the voltage measure +5 VDC?
4 1. Measure the voltage between the
violet wire and frame ground.
2. Does the voltage measure 0 VDC?
5 1. Remove the rear cover and rear shield.
2. Measure the voltage at J407B-16 on
the engine control board.
3. Alternately interrupt the sensor
4. Does the voltage toggle between +5
and 0 VDC?
3-38
Wiring and Plug/Jack Map References
Yes
Go to step 5.
Go to step 4.
Inspect the wiring
harness for
damage and
replace, if
necessary.
Replace the waste
cartridge full
sensor.
Replace the
engine control
board.
Phaser 7750 Printer Service Manual
No
Go to step 2.
Go to step 3.
Replace the
engine control
board.
Inspect the wiring
harness for
damage and
replace, if
necessary.
Inspect the wiring
harness for
damage and
replace, if
necessary.