Ricoh FT4460, Service Manual, Page: 346 / 413

28 February 1989
1.5 VERTICAL BLACK BANDS - 1
-
Phenomenon -
Vertical black bands on the
copy (paper feed direction).
- Possible Causes -
1.
2 .
3.
4.
5.
The inlet seal (mylar strip) on the development unit is defective; toner
scatters and coats the toner shield glass.
Optics unit components are dirty.
The cleaning brush bristles are crushed or contaminated with foreign
substances.
The cleaning blade is dirty or damaged.
Toner density is too high.
- Actions -
NOTE: See if the black bands shift when the reproduction ratio is changed.
1.
2.
3 .
4.
5.
If so, the problem is in the optics unit.
Check and replace the inlet seal if defective; then, clean the toner shield
glass.
Clean the optic unit components.
Replace the cleaning brush.
Press the blade release lever two or three times to clean the edge of the
cleaning blade. If this doesn’t correct the problem, replace the blade.
See section 1.16 (TONER DENSITY TOO HIGH).
NOTE: A deteriorated exposure lamp can
also cause black bands on the copy.
A slack filament can cause dirty black
bands.
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