Ricoh FT5034, Service Manual

Page: 127 / 139

6. Horizontal Black Line
Problem Cause
Black lines
perpendicular to
the paper feed
direction appear
on the copy
image. 1. The drum is scratched.
2. The hot roller is scratched.
3. Toner adheres to the drum surface as a result of blade pressure.
Note: Check the interval of the appearance of horizontal black lines.
If black lines appear at 251 mm intervals, the cause is a scratched drum or
toner build-up.
If black lines appear at 125 mm intervals, the cause is a scratched hot roller.
4. If there is no scratch on the drum surface
(1) Due to inefficient cleaning, a sticky foreign substance is attached, causing
the piled-up toner to attach to the drum surface when the copier stops.
CASE (1).
[Cause]
If black lines appear at 151 mm from the leading edge of the paper.
[Check]
1) Check whether this black line appears at 151
mm intervals after making copies of other sizes (A4, B4 ....).
2) After making several copies, this black line
disappears at the cleaning section.
(2) When the trailing edge of the paper is separated from the drum surface, a
line of charge is transferred to the drum surface.
When the charged line on the drum contacts the cleaning blade, toner
particles adhere to the drum.
Case (2)
[Cause]
If black lines appear at 76 ~ 86 mm from the leading edge of the paper.
[Check]
1) Check that the black line appears at 102~107 mm intervals on A4
lengthwise copies.
2) Check whether this black line appears on the second
copy (not in single copy mode).
Horizontal Black Line
A3 copy
Horizontal Black Line
A3 copy
76 ~ 86 mm
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