Oki Data CONFIDENTIAL
43163501TH Rev. 1
129 /
7.5.2.(1)
LCD Display Malfunction
(1-1)
Nothing is displayed in LCD
F4 (fuse) of main board (BLA
PCB)
Connection of low-voltage
power supply unit and main
board (BLA PCB).
Connection cable between
low-voltage power supply unit
and main board (BLA PCB).
Connection of main board
(BLA PCB) and operation
panel board (WHIPCB).
FFC connects between main
board (BLA PCB) and
Operation panel board
(WHIPCB).
AC power supply supplied to
the printer.
Voltage setting of low-voltage
supply unit (110V/ 230V).
The 5V power supply supplied
to the main board (BLA PCB).
The 3.3V power supply
supplied to the Operation
panel board (WHI PCB).
The 5V power supply and
24V power supply supplied to
the main board (BLA PCB)
Confirmation Tasks
Confirm whether F4 is cut.
Confirm whether the cord is normally connected from a low-
voltage power supply to the POW connector of main board
(BLA PCB)
Check whether incompletely connection and oblique insertion
of connector exist.
Confirm whether it is disconnected.
Confirm whether the coating peeling off exists.
Check whether Cord ASSY defect exists such as the wire
pulled out.
Confirm whether 7-pole FFC is normally connected with the
OP732 connector of main board (BLA PCB).
Confirm whether 7-pole FFC is normally connected with the
CN1 connector of operation panel board (WHI PCB).
Check whether incompletely connection and oblique insertion
of connector exist.
Disconnection check by the tester. Confirm the coating peeling
off by visual inspection.
Confirm the supplied voltage of the AC power supply.
Measurement of supplied AC voltage.
Confirm the power supply setting of the equipment used.
(Confirm the short plug of the low-voltage supply setting
switch. Short plug Have/None=100V /230V)
Confirm the 5V power supply by 5 and 6pin of POW connector
of the PU board (BLA PCB).
Confirm the 3.3V power supply by 1pin of CN1 connector of
Operation panel board (WHI PCB).
Confirm whether short circuit exists by the POW connector of
the main board.
If
3, 4pin: 24V
5, 6pin: 5V
7, 8, 9pin:0VL
1, 2 pin:0VP are measured, the position of short circuit can be
located.
Pulling out the cords connected with the main board (BLA
PCB) one by one, and then fix the position of short-circuit.
Action at NG
Exchange F4 or
BLAPCB.
Try to plug in the code
normally.
Replace it with normal
low-voltage power
supply unit.
Try to insert the cord
normally.
Replace it with normal
FFC.
Supply the AC power
supply.
Adjust the low-voltage
power supply setting.
Exchange the Low-
voltage power supply.
Exchange F4 or
BLAPCB.
Exchange the short
parts.
(1-1-1) Fuse confirmation
(1-1-2) Check the connection
(1-1-3) Peripheral check of power supply
(1-1-4) Short circuit confirmation of power supply
Confirmation Items