Oki B721 Maintenance Manual

Oki Data CONFIDENTIAL
45487001TH Rev.1
6-70 /
6. Troubleshooting procedure
6.5.3.(4) Black banding/black streaking in vertical direction
(4-1) Thin vertical line (with color) (Refer to Figure 6-2 D.)
Check item Check work
Actions to be taken
at NG
(4-1-1) ID unit condition
Filming of the ID
unit
Is print attempted without toner? Replace toner
cartridge with
new one. If
replacement
does not solve
the problem,
replace the
ID unit. 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.
(4-2) Thin vertical line (without color) (Refer to Figure 6-2 F.)
Check item Check work
Actions to be taken
at NG
(4-2-1) LED head condition
LED head Is any foreign material attached on the light
emitting surface of the cell fox lens of the LED
head?
Remove
the foreign
material.
(4-2-2) Condition of paper running path
Paper running path Check that any burr that may scatter the un-
fused toner on the paper running path does
not exist.
Remove the
burr.
6.5.3.(5) Periodic abnormalities (Refer to Figure 6-2 E.)
(5-1) Periodic abnormality occurs in vertical direction
Check item Check work
Actions to be taken
at NG
(5-1-1) Cycle
Image drum Check that the cycle is 94.3 mm.
Replace the ID
unit
Developing roller Check that the cycle is 39.7 mm.
Replace the ID
unit
Toner feed roller Check that the cycle is 66.6 mm or 72.8 mm.
Replace the ID
unit
Charge roller Check that the cycle is 37.7 mm.
Replace the ID
unit
Fuser belt Check that the cycle is 94.3 mm.
Replace the
fuser unit.
Heat roller Check that the cycle is 90.3 mm.
Replace the
fuser unit.
Transfer roller Check that the cycle is 51.5 mm.
Replace the
Transfer Roller.
If any attempt
of using new
consumable
item as a trial
is going to
be made, be
sure to use
the System
Maintenance
Menu FUSE
KEEP MODE.

Oki B721 Specifications

General

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