Kyocera FS-6950DN Service Manual page 58

2F7
(5) Black horizontal streaks.
Print example
Defective drum unit's ground.
Defective drum unit.
(6) Black vertical streaks.
Print example
Flawed main charger roller.
Dirty or flawed drum.
Defective drum unit.
Defective developing roller (developer
unit).
(7) Unsharpness.
Print example
Defective paper specifications.
EcoPrint mode setting.
Defective transfer roller.
Poor contact of engine PWB's trans-
fer bias output terminal and printer's
contact (spring).
1-4-12
Causes
Causes
Causes
Check procedures/corrective measures
Defective drum unit's ground. The contact (spring) in the drum
unit and its counter part, the drum grounding terminal in the
printer, must be in a good contact. (See page P.1-4-9, refer to
figure 1-4-3)
If a drum unit which is known to work normally is available for
check, replace the current drum unit in the printer with the nor-
mal one. If the symptom disappears, replace the drum unit
with a new one (See page P.1-5-11).
Check procedures/corrective measures
Replace the main charger unit (See page P.1-5-12).
Clean the drum or, if it is flawed, replace the drum unit (See
page P.1-5-11).
A streak of toner remaining on drum after printing means that
the cleaning blade (in the drum unit) is not working properly.
Replace the drum unit (See page P.1-5-11).
If a drum unit which is known to work normally is available for
check, replace the current drum unit in the printer with the nor-
mal one. If the symptom disappears, replace the drum unit
with a new one (See page P.1-5-11).
If a developer unit which is known to work normally is available
for check, replace the current developer unit in the printer with
the normal one. If the symptom disappears, replace the devel-
oper unit with a new one.
Check procedures/corrective measures
Paper with rugged surface or dump tends to cause unsharp
printing. Replace paper with the one that satisfies the paper
specifications.
The EcoPrint mode can provides faint, unsharp printing
because it acts to conserve toner for draft printing purpose.
For normal printing, turn the EcoPrint mode off by using the
operation panel. For details refer to the printer's operation
guide.
If the transfer roller is contaminated with toner, clean the trans-
fer roller using a vacuum cleaner or by continuously printing a
low density page until the symptom has faded away.
Check the installation position of the engine PWB.
(See page P.1-5-22 and P.1-4-9, refer to figure 1-4-3)