User manual

98.05.08.09.00
Color LaserWriter 12/600 PS Troubleshooting 2–34
To minimize this effect, try to avoid large flat areas of color, as they will
most readily reveal this type of banding, and keep the printer away from
machinery that might cause excessive vibration. In addition, take care
in maintaining the printer and in keeping it clean and level.
Banding caused by mechanical processes can be remedied. See the
print quality issue below.
4 There is a repetitive horizontal defect on my pages.
Refer to “Roller Diameters” in this chapter. Defects that repeat at a
constant spacing are usually the result of dirty or damaged rollers.
5 I am getting oil spots on the paper. What can I do to prevent this?
The purpose of silicone oil is to prevent offsetting of toner onto the
fuser rollers. Oil spots on paper should occur infrequently, and then
usually on the back of the page. Some factors that are known to
increase the incidence of oil staining are
• Failure to remove the orange spacers from inside the fuser access
door.
• Turning the printer on and off repeatedly over a short period of time
(e.g. five times in an hour).
• A printer coming out of a very long standby mode may exhibit some
staining on the first couple of pages.
• Using recycled paper over a prolonged period can plug the oil pan
filter which in turn can cause long streaks on the back of the paper.
6 I am getting small amounts of toner on the printed page. What can I do
to prevent it?
Cleaning the toner off the following areas should eliminate the
problem:
• Clean the density sensor and separation discharge wire with the
brush provided, as described on page 223 of the user guide. Clean
the paper pickup area as described on page 226 of the user guide.
• Print ten blank pages. This will help clean toner off rollers.
7 What does the “Best” print quality selection do for the printer?
Selecting the “Best” mode in the print dialog box adds one rotation to
the transfer drum (see “Stage 4: Transfer” under “Stages of Imaging” in
Chapter 1). This additional rotation occurs before any imaging to allow
the paper to fully adhere to the transfer drum. This precaution corrects
small registration problems that might occur during the imaging of the
magenta layer, the first color that is transferred.