Xerox 7700DX Service Manual - Page 99

Error 78 Waste Toner Cartridge Full Detection, Sensor Failure, Error 80 Engine Logic Board Failure

Page 99 highlights

Error Code Chain / Link Front Panel Message 78 09-358 ERROR 78 WASTE TONER CARTRIDGE FULL DETECTION SENSOR FAILURE Remove the Waste Cartridge Sensor Holder without disconnecting the harnesses (RRP 23, on page 7-178). Measure the voltage between the yellow wire to the Waste Cartridge Full Sensor and frame ground and alternately interrupt the Waste Cartridge Full Sensor. Does the voltage toggle between +5 VDC and 0 VDC? Yes No Measure the voltage between the gray wire to the Waste Cartridge Full Sensor and frame ground. Does the voltage measure +5 VDC? Yes No Remove the Rear Cover (RRP 1, on page 7-154) and Rear Shield (RRP 9, on page 7-163). Measure the voltage at P406A-3 (see figure page 2-46) on the Engine Control Board. Does the voltage measure +5 VDC? Yes No Replace the Engine Control Board (RRP 42, on page 7-206). Inspect the wiring harness between the Engine Board and the Waste Cartridge Full Sensor. Repair or replace the harness as necessary. Measure the voltage between the violet wire to the Waste Cartridge Full Sensor and frame ground. Does the voltage measure 0 VDC? Yes No Inspect the wiring harness between the Engine Board and the Waste Cartridge Full Sensor. Repair or replace the harness as necessary. Replace the Waste Cartridge Full Sensor. Remove the Rear Cover (RRP 1, on page 7-154) and Rear Shield (RRP 9, on page 7-163). Measure the voltage at P406A-2 (Voltage Measurements on page 2-46) on the Engine Control Board. Alternately interrupt the Waste Cartridge Full Sensor again. Does the voltage toggle between +5 VDC and 0 VDC? Yes No Inspect the wiring harness between the Engine Board and the Waste Cartridge Full Sensor. Repair or replace the harness as necessary. Replace the Engine Control Board (RRP 42, on page 7-206). 80 04-341 ERROR 80 ENGINE LOGIC BOARD FAILURE 04-343 Switch printer power Off, then On. If the problem persists, replace the Engine Control Board (RRP 42, on page 7-206). Phaser 7700 Color Laser Printer Service Manual 2-69

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Phaser 7700 Color Laser Printer Service Manual
2-69
78
09-358
ERROR 78 WASTE TONER CARTRIDGE FULL DETECTION
SENSOR FAILURE
Remove the Waste Cartridge Sensor Holder without disconnecting the harnesses (RRP 23,
on page 7-178).
Measure the voltage between the yellow wire to the Waste Cartridge Full Sensor and frame
ground and alternately interrupt the Waste Cartridge Full Sensor.
Does the voltage toggle between +5 VDC and 0 VDC?
Yes No
Measure the voltage between the gray wire to the Waste Cartridge Full Sensor and
frame ground.
Does the voltage measure +5 VDC?
Yes No
Remove the Rear Cover (RRP 1, on page 7-154) and Rear Shield
(RRP 9, on page 7-163).
Measure the voltage at P406A-3 (see figure page 2-46) on the Engine Control
Board.
Does the voltage measure +5 VDC?
Yes No
Replace the Engine Control Board (RRP 42, on page 7-206).
Inspect the wiring harness between the Engine Board and the Waste Cartridge Full
Sensor.
Repair or replace the harness as necessary.
Measure the voltage between the violet wire to the Waste Cartridge Full Sensor and
frame ground.
Does the voltage measure 0 VDC?
Yes No
Inspect the wiring harness between the Engine Board and the Waste Cartridge Full
Sensor.
Repair or replace the harness as necessary.
Replace the Waste Cartridge Full Sensor.
Remove the Rear Cover (RRP 1, on page 7-154) and Rear Shield (RRP 9, on page 7-163).
Measure the voltage at P406A-2 (Voltage Measurements on page 2-46) on the Engine Control
Board.
Alternately interrupt the Waste Cartridge Full Sensor again.
Does the voltage toggle between +5 VDC and 0 VDC?
Yes No
Inspect the wiring harness between the Engine Board and the Waste Cartridge Full
Sensor.
Repair or replace the harness as necessary.
Replace the Engine Control Board (RRP 42, on page 7-206).
80
04-341
04-343
ERROR 80 ENGINE LOGIC BOARD FAILURE
Switch printer power Off, then On.
If the problem persists, replace the Engine Control Board (RRP 42, on page 7-206).
Error
Code
Chain /
Link
Front Panel Message