Lexmark C77X, Service Manual

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Service Manual
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The Laser printing process heats paper to high temperatures of 180°C (356°F) for non-MICR applications. Use
only paper able to withstand these temperatures without discoloring, bleeding, or releasing hazardous
emissions. Check with the manufacturer or vendor to determine whether the paper chosen is acceptable for
laser printers.
When loading paper, note the recommended print side on the paper package, and load paper accordingly.
Paper characteristics
The following paper characteristics affect print quality and reliability. It is recommended that these guidelines are
followed when evaluating new paper stock.
For detailed information, see the Card Stock & Label Guide available on the Lexmark Web site at
www.lexmark.com/publications.
Weight
The printer can automatically feed paper weights from 60 to 176 g/m
2
(16 to 47 lb bond) grain long. Paper lighter
than 60 g/m
2
(16 lb) might not be stiff enough to feed properly, causing jams. For best performance, use 90 g/m
2
(24 lb bond) grain long paper. To use paper narrower than 182 x 257 mm (7.2 x 10.1 in.), it is recommended that
the weight be greater than or equal to 90 g/m
2
(24 lb bond).
Curl
Curl is the tendency of media to curve at its edges. Excessive curl can cause paper feeding problems. Curl can
occur after the paper passes through the printer, where it is exposed to high temperatures. Storing paper
unwrapped in hot, humid, cold and dry conditions, even in the trays, can contribute to paper curling prior to
printing and can cause feeding problems.
Smoothness
The degree of smoothness of paper directly affects print quality. If the paper is too rough, the toner does not fuse
to the paper properly, resulting in poor print quality. If the paper is too smooth, it can cause paper feeding or print
quality issues. Smoothness needs to be between 100 and 300 Sheffield points; however, smoothness between
150 and 250 Sheffield points produces the best print quality.
Moisture content
The amount of moisture in the paper affects both print quality and the ability of the printer to feed the paper
properly. Leave the paper in its original wrapper until it is time to use it. This limits the exposure of the paper to
moisture changes that can degrade its performance.
Condition paper while it is still in the original wrapper. To condition it, store it in the same environment as the
printer for 24 to 48 hours before printing to let the paper stabilize in the new conditions. Extend the time several
days if the storage or transportation environment is very different from the printer environment. Thick paper may
also require a longer conditioning period because of the mass of material.
Grain direction
Grain refers to the alignment of the paper fibers in a sheet of paper. Grain is either grain long , running the length
of the paper, or grain short , running the width of the paper.
For 60 to 90 g/m
2
(16 to 24 lb bond) paper, grain long fibers are recommended.
Fiber content
Most high-quality xerographic paper is made from 100% chemically pulped wood. This content provides the
paper with a high degree of stability resulting in fewer paper feeding problems and better print quality. Paper
containing fibers such as cotton possesses characteristics that can result in degraded paper handling.