Lexmark C910 User Reference Manual page 146

Problem
Toner covers the background of
the page.
The page has 100% coverage of
one color.
Light lines or streaks appear on
the printed page.
The page is blank or one of the
colors is missing.
Toner smears or rubs off the
page.
Action
Make sure the affected toner cartridge is completely installed.
Replace the photodevelopers. If the page is black, you can replace just the
black photodeveloper. If the page is another color, replace all three of the
color photodevelopers. See
Clean the LEDs. See Cleaning the
Remove the toner cartridge that matches the color of the lines or streaks and
gently shake it back and forth to distribute the toner evenly. Reinsert the
toner cartridge and try printing the job again.
Replace the photodevelopers. If the problem only occurs when printing black,
you can replace just the black photodeveloper. If the problem occurs when
printing one of the colors, replace all three of the color photodevelopers. See
Replacing a photodeveloper.
Replace the toner cartridge that matches the color of the lines or streaks on
the page. See Replacing a toner
Replace the toner cartridge that matches the missing color on the page. See
Replacing a toner cartridge.
Make sure you're using recommended paper or other media. Refer to the
Card Stock & Label Guide for more information.
Make sure you have selected the correct
you're using.
You may need to replace the fuser. See
144
Replacing a photodeveloper.
LEDs.
cartridge.
Paper Type
Replacing the
setting for the media
fuser.