Epson Stylus Pro 7400 Service Manual page 204

EPSON Stylus Pro 7400/7800/9400/9800
INCONSISTENCIES IN DENSITY, BLURRING, OR UNEXPECTED
COLORS
When a print quality trouble such as inconsistencies in density, blurring images,
unexpected colors, or etc. occurs, perform the following items.
1. Carry out the following adjustments.
1. Nozzle Bi-D Adjustment (p.321)
2. Auto Bi-D Adjustment (P.G. 0.8/1.6) (p.330)
3. Auto Uni-D Adjustment (p.329)
If any abnormality is found by Check Nozzle (p.362)
(p.363), go to the next step.
2. If the print quality trouble appears only on a particular type of thick paper, input
the paper type in the CUSTOM PAPER in the Panel Setting menu.
(Make a custom setting for the paper using the menu. Selecting appropriate paper
feeding amount, platen gap can avoid the trouble.)
3. When the trouble occurs after replacing the C594 Main Board
Load the NVRAM parameters from the previous Main Board.
4. If the trouble still occurs even after performing the troubleshooting described
above, replace the part listed below.
PRINT HEAD (p.267)
Troubleshooting
SMUDGES ON THE PRINTED SIDE
When smudges caused by the head or etc. appear on printed side, perform the
following items.
1.
and Check Alignment
2.
3.
(p.338)
4.
5.
Troubleshooting based on Printed Result
If the smudges appear on the top or bottom margin of roll paper, expand the
margin. (Set the ROLL PAPER MARGIN in the Panel Setting menu to "TOP/
BOTTOM 15 mm".)
(Narrower margin setting (3 mm) for the high-density print job is likely to cause
smudges on the margin because the paper deforms due to a lot of ink printed on it
and its top or bottom edge sometimes contacts with the printhead.)
For thin or soft paper that cannot go through the paper path smoothly, set the
PAPER SUCTION in the CUSTOM PAPER in the Panel Setting menu to "-4".
When the smudges appear on a user-defined paper because the printed ink does
not dry fast
Correct the DRYING TIME setting in the CUSTOM PAPER of the Panel Setting
menu. The DRYING TIME is a time period from when finishing printing to when
starting cutting the paper. (Default is 0 second, and can be selected in 1-second
unit up to 10 seconds)
When the above troubleshooting does not solve the problem, check the following
items.
Check if the Pump Unit is damaged.
Check if dust, paper dust, or foreign materials that absorbed ink is adhering to
the side of the printhead.
Change the PG setting to the wider setting.
NOTE: This may deteriorate the print quality.
Revision B
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