Oki B721 Maintenance Manual

Oki Data CONFIDENTIAL
45487001TH Rev.1
6-71 /
6. Troubleshooting procedure
6.5.3.(6) Solid black printing.
(6-1) Solid black printing over the whole page
Check item Check work
Actions to be taken
at NG
(6-1-1) High voltage contacting condition
CH terminal Check that the terminal coming from the
printer body contacts with the high voltage
terminal that is located on the left side of the
ID unit when viewed from the top by visual
inspection.
Replace the
terminal of
printer side.
CH terminal Check that the high voltage terminal keeps
the normal contacting condition on the high
voltage board. Open the left cover and remove
the high voltage board. Then, check that
the terminal is not installed in the abnormal
installation condition.
Correct the
installation
condition of
the terminal
to the normal
condition.
ID unit terminal Check that the high voltage terminal of the ID
unit is contacting with the Contact Assembly
normally by visual inspection. (Refer to Figure
6-3.)
Replace the ID
unit or replace
the high voltage
board or correct
the high voltage
terminal.
If any attempt
of using new
ID unit as a
trial is going
to be made,
be sure to use
the System
Maintenance
Menu FUSE
KEEP MODE.
(6-1-2) High voltage output condition
CH output If high voltage probe is available as a
maintenance tool, open the left cover, and
check the CH output with the high voltage
probe from the soldering side of the high
voltage board. (The high voltage probe is not
an ordinary maintenance tool.)
Replace the
high voltage
board.
Figure 6-3
Ground
Charge roller
Developer roller
Toner feed roller

Oki B721 Specifications

General

Print Technology	LED
Resolution	1200 x 1200 dpi
Processor	533 MHz
Memory	256 MB
Connectivity	USB, Ethernet
Duplex Printing	Standard