Epson Stylus Pro 7700 Service Manual page 157

Epson Stylus Pro 7700/7710/7700M/7710M/7900/7910/9700/9710/9900/9910/WT7900/WT7910/9890/9908/7890/7908
Symptom Occurrence condition
Uneven color appears around Blurry uneven color appears at
the core of the CPF roll paper. the end of the CPF wrapped to
the core.
Uneven color appears • Uneven color or horizontal
approximately every 40 cm. bandings (in the CR
movement direction) can
be seen.
• The lines appear
approximately every 40 cm
(circumference of roll).
TROUBLE SHOOTING
Cause
• The CPF's coat layer gets softer and easily deformed if it becomes
hotter or more humid.
• Because the roll core's surface is uneven, pressure is partially high
in some places. If the CPF is left at a high temperature, the coated
side sticks to the backside of the CPF (Release Film side) at the area
with higher pressure. In such a case, an uneven surface is formed on
the coat layer surface and the light is diffused there, ending up in
blurry uneven color. (blocking bands)
Roll core
• If stored horizontally without the flange attached to the CPF, the
coat layer becomes soft due to the weight of the roll paper. The coat
layer and the Release Film stick together (blocking bands occur).
• Uneven color bands appear approximately every 40 cm
(circumference of roll) because the blocking bands turn white.
CPF roll
Own weight
Remedies for Print Quality Troubles
Remedy/Points to be checked
• Blocking bands may occur at points with high pressure
such as around the roll core even if the transportation
conditions (See P.152) are satisfied. For such reasons,
additional length is included.
• Around the roll core, uneven color or the trace of the core
may appear on the media. If they appear, replace it with a
new roll.
• When printing on a blocking band, the band becomes
hard to see, but it will be still visible on the area not
printed.
• When the CPF is stored horizontally, make sure to attach
the flange. Otherwise, discoloration or uneven color may
occur. When the CPF is stored horizontally; even if the
container box is used, make sure to attach the flange for
packing.
• When printing on a blocking band, the band becomes
hard to see, but it will be still visible on the area not
printed.
Revision I
157
Confidential