Ricoh FW830, Service Manual

Page: 156 / 227

4.3 DRUM CURRENT ADJUSTMENT
NOTE: a) The drum currents vary with environmental conditions such as
humidity and atmospheric pressure. Generally it is not necessary
to adjust the drum currents because they have already been
adjusted for a wide range of environments at the factory.
b) Drum current adjustment is necessary whenever the power packs
are replaced; adjustment may also be necessary to correct
problems with paper separation, incomplete toner transfer, or
image density.
c) Make sure that the main switch is turned off when you change the
range on the digital multimeter. If it is not, the multimeter may be
damaged.
4.3.1 Preparation
1. Turn off the main switch and remove the following parts:
•
Left middle cover
•
Right middle cover
•
Pick-off pawl unit (See Drum Replacement)
•
Cover plate (See Drum Replacement)
•
Drum (See Drum Replacement)
2. Clean or replace each corona wire and clean the corona units.
NOTE: When the wire is cleaned with a dry cloth, make sure that the
wire does not become stretched.
CORONA 31 December 1992
5-16