Kyocera FS-6950DN Service Manual page 57

(3) Dropouts.
Print example
Defective developing roller (developer
unit).
Defective drum (drum unit).
Fuser unit (heat roller or press roller).
Defective paper specifications.
Defective transfer roller installation.
Defective engine PWB (transfer bias
output circuit).
(4) Black dots.
Print example
Defective drum unit.
Causes
Causes
Check procedures/corrective measures
If the defects occur at regular intervals of 39 mm/1
page P.2-4-2), the problem may be the damaged developing
roller (in the developer unit). Replace developer unit.
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 (See page P.1-5-10).
If the defects occur at regular intervals of 94 mm/3
page P.2-4-2), the problem may be the damaged drum (in the
drum unit). Replace drum unit.
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 the defects occur at regular intervals of 82 mm/3
mm/3 " (See page P.2-4-2), the problem may be the dam-
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aged heat roller or press roller (in the fuser unit). Replace
fuser unit (heat roller or press roller).
If a fuser unit which is known to work normally is available for
check, replace the current fuser unit in the printer with the nor-
mal one. If the symptom disappears, replace the fuser unit
(heat roller or press roller) with a new one (See page P.1-5-
15).
Paper with rugged surface or dump tends to cause dropouts.
Replace paper with the one that satisfies the paper specifica-
tions.
The transfer roller must be supported by the bushes at the
both ends. Clean the bush to remove oil and debris. Replace
the transfer roller if necessary (See page P.1-5-13).
Replace the engine PWB (See page P.1-5-22).
Check procedures/corrective measures
If the defects occur at regular intervals of 94 mm/3
page P.2-4-2), the problem may be the damaged drum (in the
drum unit). Replace drum unit.
If the defects occur at random intervals, the toner may be leak-
ing from the developer unit or drum unit. Replace developer
unit or drum unit (See page P.1-5-10 or P.1-5-11).
2F7-1
" (See
9/16
" (See
11/16
" or 93
1/4
" (See
11/16
1-4-11