Ricoh pro c901, Technical Bulletin

Page: 455 / 586

T
echnical
B
ulletin
PAGE: 3/75
Reissued:21-Apr-14
Model:
Aries-P1.5/C1.5
Date:
10-Mar-14
No.:
RM077107b
Drum scratches caused by narrow PG
Excerpt from RTB RM077099
Drum scratches occur because the PG (potential gap; gap between the development roller
and drum) is narrower than the specification. In this condition, stress is applied to the
developer in the development process because the developer is forced to move through a
narrow gap, generating excess electrical current along with heat and pressure. As a
result, developer adheres to the surface of the development roller and toner continues to
build up, eventually scratching the drum.
Correct way to fasten the drum knob
Excerpt from “
Correct Procedure for Fastening the Drum Knob” RTB RG178128d
See RTB RG178128d for details.

Always pull out the developer unit and remove the drum cleaning unit when fastening
the drum knob.

Never attempt to further fasten the drum knob when the drum cleaning unit is installed.
]
This is important in preventing the following problems:
1) Inconsistent density between left and right sides on a page
2) Toner adheres to the development rollers
3) Drum scratches caused by development rollers adhered with toner
4) Toner clumps caused by narrow PG
Dev roller
Drum
Base board
Development area
Drum
Base board
Developer
applies
pressure to the
dev roller.
Dev roller
Scratches are
generated on the
drum surface.
As toner adhesion
progresses toner
piles up higher on
certain areas.
Toner adhesion
Toner
adhesion
progresses.
Standard PG Narrow PG
Development area
Development area
Drum
Base board
Developer
applies
pressure to the
dev roller.
Dev roller
PG
PG