Xerox 7750DXF - Phaser Color Laser Printer Service Manual page 175

One Color Is Faded or Missing
1. Under high toner-coverage conditions, toner may be depleted during the toner
low state but before the toner out message is displayed
2.
Is the toner low or near empty? Remove the toner cartridge and inspect the top
of the feed tube. Replace the toner cartridge if necessary. Ensure that genuine
Xerox toner is installed.
3. Calibrate for Paper
Run the
4.
Check the transfer setting before running calibrate paper. If the value is -4, you
need to adjust the transfer settings.
5. Remove the imaging unit and verify that the laser shutter opens and closes
using the Service Diagnostics Shutter Solenoid test.
6. Inspect and test the toner auger system. Ensure that the toner auger motor
operates. Ensure that the toner dispense assembly is carrying toner from the
toner cartridge to the developer.
7. Remove the accumulator belt assembly and inspect the high-voltage
connectors on the back side to ensure they are not damaged.
8.
Inspect the high-voltage wiring leading to the accumulator belt assembly for
damage.
9. Verify that the developer is seated properly.
10. Replace the developer beads.
11. If the missing or faded primary color appears as speckle on the entire page, the
high-voltage wire leading to that color's developer housing is grounded.
Inspect the high-voltage wiring harness and power supply. Repair/replace as
necessary.
12.
Replace the laser unit.
13. Swap the leads of the affected color with another color on the T2 HVPS. If the
symptom changes, replace the T2 high-voltage power supply.
14.
Replace the T3 high-voltage power supply.
Print-Quality Troubleshooting
routine.
3041-39
5-15