Xerox 7700DX - Phaser Color Laser Printer Service Manual page 109

Error Chain /
Code Link
120 12-260
121 12-262
Remove the Finisher Rear Cover (RRP 72, on page 11-330).
Remove the sensor from the top of the eject motor mount bracket (RRP 76, on page 11-335).
Enter Service Diagnostics Mode.
From the Main Menu, select "Sensor Tests/Finisher Sensors/Miscellaneous."
Manually actuate the Eject Clamp Home Sensor and observe the display.
Does display indicate the Eject Clamp Home Sensor toggling between H & L?
Yes No
Remove the Rear Cover and the Board Cover (RRP 72, on page 11-330).
Measure the voltage between the Finisher Control Board P849-5
(see figure page 2-46) and Finisher frame ground.
Again manually actuate the Stack Height Sensor.
Does the voltage toggle between +5 VDC and 0 VDC?
Yes No
Measure the voltage at the Eject Clamp Home Sensor pin 2 (yellow) and
Finisher frame ground.
Once again manually actuate the Eject Clamp Home Sensor.
Does the voltage toggle between +5 VDC and 0 VDC?
Yes No
Measure the voltage at Eject Clamp Home Sensor pin 1 (gray).
Does the voltage measure +5 VDC?
Yes No
A B C D
FINISHER ERROR 120 EJECT CLAMP HOME SENSOR ON
FAILURE
FINISHER ERROR 121 EJECT CLAMP HOME SENSOR OFF
FAILURE
Measure the voltage between the Finisher Control Board P849-6
(see figure page 2-46)and Finisher frame ground.
Does the voltage measure +5 VDC?
Yes No
Replace the Finisher Control Board (RRP 77, on page 11-336).
Repair or replace the wiring harness between the Finisher Control
Board and the Eject Clamp Home Sensor.
Phaser 7700 Color Laser Printer Service Manual
Front Panel Message
2-79