Oki B721 Maintenance Manual

Oki Data CONFIDENTIAL
45487001TH Rev.1
6-59 /
6. Troubleshooting procedure
Check item Check work
Actions to be taken
at NG
(10-2-3) AC power input for the fuse
AC power voltage
from the low
voltage power
supply
Check if the AC voltage for heater is normally
supplied or not.
Power supply CN03 connector
, between
pin-1 and pin-4, and between pin-2 and pin-3.
Replace the low
voltage power
supply.
Heater ON signal
that is output
from PU to the
low voltage power
supply
Check that the heater ON signal goes active
at the warming up timing, or not.
"L" active while ON.
Power connector
of the PU/CU board,
between pin-24 and pin-26.
Replace the
PU/CU board.
6.5.2.(11) Motor fan error (Errors 122, 127, 128, 918)
(11-1) The low voltage power supply fan does not rotate immediately after the power is
turned on.
Check item Check work
Actions to be taken
at NG
(11-1-1) Cable connection condition and wiring condition
Cable connection
condition and
wiring condition
of the low voltage
power supply fan
and those of the
fuser fan
Check if the connectors are connected
normally or not.
Check if extra length of the cables does not
touch the fan blade or not.
Correct the
connection
condition of
the connectors.
Correct the
cable wiring
route. Replace
the fan.
(11-2) Rear fan does not rotate during the Duplex printing.
Check item Check work
Actions to be taken
at NG
(11-1-2) Cable connection condition and wiring condition
Cable connection
condition and
wiring condition of
the Duplex fan
Check if the connectors are connected
normally or not.
Check if extra length of the cables does not
touch the fan blade or not.
Correct the
connection
condition of
the connectors.
Correct the
cable wiring
route. Replace
the fan.
24V power supplied
to the fan
Check if the fuse F1 of the PU/CU board has
blown out or not.
Replace the
PU/CU board.

Oki B721 Specifications

General

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