Ricoh pro c901, Technical Bulletin

Page: 422 / 586

T
echnical
B
ulletin
PAGE: 1/3
Model:
Aries-P1.5/C1.5, AG-P1/C1, AGL-P1/C1
Date:
29-Nov-13
No.:
RM077098
Subject:
Summary of development unit originating problems
- Toner degradation -
Prepared by:
J. Kobayashi
From:
PP Tech Service Dept., 1st PP Tech Service Sect.
Classification: Troubleshooting
Mechanical
Paper path
Product Safety Part information
Electrical
Transmit/receive
Other ( ) Action required
Service manual revision
Retrofit information
Tier 2
General
This bulletin summarizes the information announced in previously released RTBs for
image quality problems originating in the development unit and provides an explanation of
the differences between toner degradation and developer degradation along with the
correct actions required to avoid unneeded developer replacements, which in fact, often
take place without successful results due to misunderstanding toner degradation and
developer degradation.
How does toner degrade?
Toner degrades when fresh toner is not supplied to the development unit due to its low
consumption rate, which is caused by the following 3 factors:
z Low image coverage ratio
z Idling of C, M, Y development units when printing in B/W mode
z Idling of the mainframe while optional devices are in operation
Degrading
process
Fresh
toner
Degraded
toner
Silica (additive)
Toner
Disintegrated
silica
Silica (additive)
Toner consumed in print
operations
Dev unit
Fresh toner supplied proportionately
to the consumption rate
Mixing applies
stress to the toner