Xerox 7750DXF - Phaser Color Laser Printer Service Manual page 181

Random Missing Spots
There are small areas of the image that
are extremely light or are missing
entirely. These missing areas form
spots that are localized to small areas of
the page. The printer displays no error
code. A small number of occasional
missing spots is normal.
1.
If a toner low message is
displayed, replace the toner
cartridge in question.
2.
Ensure that the loaded media
matches the front panel settings.
3. Try using an approved media to
see if the spots still appear.
4.
Run the Calibrate for Paper
routine. From the front panel's
Printer Setup
Calibration
Calibrate for
5.
This could be cold offset. Set the paper type at the printer's front panel to one
type heavier.
6.
Run the solid fill test pages. From the front panel's
Print Quality
select
7. If the missing spots only occur in a single primary color, replace the developer
housing assembly.
Print-Quality Troubleshooting
Menu, select
Setup, then select
Paper.
Problems, then select
Troubleshooting
Solid Fill Pages.
3041-46
Menu,
5-21