Specifications

■ Fuzzy print. On a laser printer, characters that are suddenly fuzzy or unclear are probably the
result of using paper that is slightly damp. On an inkjet printer, fuzzy or smeary characters can
result when you use various types of paper not specifically intended for inkjet printing. This
also can occur if a problem exists with the connection between the print cartridge and the cra-
dle. Try reinstalling the print cartridge.
■ Variable print density. If you find that some areas of the page are darker than others when using
a laser printer, the problem is probably due to the distribution of the toner on the photorecep-
tor. The most common cause for this is uneven dispensation of the toner as its container emp-
ties. Removing the toner cartridge and shaking it from side to side redistributes the toner and
should cause it to flow evenly. You can also use this technique to get a few more pages out of a
toner cartridge after the printer has registered a “toner low” error. If your printer consistently
produces pages with the same varied print density, the problem could be the printer’s location.
If the unit is not resting on a level surface, the toner can shift to one side of the cartridge,
affecting the distribution of the toner on the page. Your printer also might have a light leak
that is causing one area of the photoreceptor to be exposed to more ambient light than others.
Moving the printer away from a bright light source can sometimes remedy this problem.
■ Dirty or damaged corotrons. A laser printer’s corotrons (corona wires) apply electrostatic charges
to the photoreceptor and the paper. If the transfer corotron (which charges the paper) has
clumps of toner or paper fragments on it, it can apply an uneven charge to the paper, and you
might see faint or fuzzy white lines running vertically down your printed pages. All-black or all-
white pages can be caused by a broken charger or transfer corotron, respectively. A toner car-
tridge that contains the photoreceptor drum typically includes the charger corotron as well, so
replacing the cartridge can remedy some of these problems. You also can (gently!) clean a dirty
corotron with a lint-free foam swab or other material recommended by the manufacturer. If you
use a cotton swab, be sure not to leave cotton fibers behind on the wires. The transfer corotron
is usually built into the printer (and not the cartridge) and will require professional servicing if
it is broken. These components are made of fragile wires, so be very careful when you clean
them. Some low-cost printers use rollers instead of corona wires.
■ Sharp vertical white lines. A sharp white line extending vertically down the entire length of your
laser-printed pages that does not go away when you shake the toner cartridge is probably
caused by dirt or debris in the developer unit that is preventing the unit from evenly distribut-
ing the toner onto the photoreceptor. Again, if the toner cartridge includes the developer unit,
replacing it is the simplest fix. If not, your printer might have a mechanism that enables you to
remove the developer roller for cleaning or even a tool designed to remove dirt from the roller
while it is in place. You also might be able to clean the roller by slipping the corner of a sheet of
paper down the slots between the roller and the metal blades on either side of it.
■ Regularly spaced spots. If your laser-printed pages have a spot or spots that are consistently left
unprinted, the cause might be a scratch or other flaw in the photoreceptor drum or a build-up
of toner on the fusing roller. You can often tell the difference between these two problems by
the distance between the spots on the page. If the spots occur less than three inches apart (ver-
tically), the problem is probably caused by the fusing roller. Because the photoreceptor drum
has a larger diameter than the fusing roller, the spots it produces would be farther apart or per-
haps only one on a page. Replacing a toner cartridge that contains the photoreceptor drum and
the fuser cleaning pad (an oil-impregnated pad that presses against the fuser roller to remove
excess toner) should solve either of these problems. Otherwise, you probably will have to
replace the drum assembly or the fuser cleaning pad separately. Some printers require profes-
sional servicing to replace the photoreceptor drum. To be sure where the problem lies, check the
printer vendor’s Web site or the printer documentation for the circumferences of the fusing
roller, photoreceptor drum, and other rollers in the printer and where they leave marks on the
paper.