Lcd Display Error; Lcd Does Not Display Anything - Oki C610n Maintenance Manual

Oki Data CONFIDENTIAL

7.5.2. (1) LCD display error

Memo For the numbers from
refer to section 7.5.2 (19) "Wiring diagram".

(1-1) LCD does not display anything.

Check item
(1-1-1) Check the fuse.
F3,F5 (fuse) of the Check if F3,F5 has blown out or not.
CU/PU board
(1-1-2) Check the system connection
Connection between Check if the cable from the low voltage power
the low voltage supply to the POWER connector
power supply unit PU board is normally connected or not.
and the CU/PU
Check if the connector is connected only in the
board.
half-way or not, and check if the connector is
inserted in slanted angle or not.
Cable assembly Check if the cable is half-open circuit.
connecting the low Check if sheath of the cable has not peeled off
voltage power supply or not.
unit and the CU/PU Check if the cable assembly is defective such as
board. internal wires are disconnected or not.
Connection between Check if the 11-conductor FFC is connected
the CU/PU board to the OPE connector
and Operator Panel normally or not.
Check if the 11-conductor FFC is connected
to the OPE connector
normally or not.
Check if the connector is connected in the half-
way only or not, and check if the connector is
inserted in a slanted angle or not.
FFC connecting the Check if the cable has open circuit or not with
CU/PU board and VOM. Check if sheath of the cable has not
the Operator Panel peeled off or not by visual inspection.
board
44205301TH Rev.1
through after name of the respective connectors,
Action to be taken
Check work
Replace CU/PU
board.
Re-connect the
of the CU/ cable normally.
Replace the
cable with the
normal cable.
Note!
Re-connect the
of the CU/PU board cable normally.
of the CU/PU board
Replace the FFC
with the normal
FFC.
Check item
(1-1-3) Check the peripherals of the power supplies
Primary AC power
source that is
connected to the
printer.
at NG
Voltage setting of
the lower voltage
power supply unit
(100V system/230V
system)
5V power that is
supplied to the CU/
PU board.
3.3V power that
is supplied to the
Operator Panel.
(1-1-4) Check that power supply circuit has no short-circuit.
5V power and 24V
power that are
supplied to the CU/
PU board.
7. Troubleshooting and repair procedure
Check work
Check the supplied voltage of the AC power
source.
Measure the AC voltage supplied.
Check the power voltage setting of the
equipment in use.
(Check the shorting plug that is used for
selection of the voltage power supplies.)
Shorting plug is Used/Not used = 100V system/
230V system.
Check for the 5V power supply at pin-1, 2, 3 of
the POWER connector of the CU/PU board.
Check for the 3.3V power supply at pin-11 of the
CN connector of the Operator Panel board.
Check that power supply circuit has no short-
circuit at the POWER connector no. 10 of the
CU/PU board. The follow voltage must appear
respectively.
pins-7, 8 and 9: 24V
pin-1, 2 and 3: 5V
pin-4, 5 and 6: 0VL
pins-10, 11 and 12: 0VP
If any voltage does not appear and short-circuit
is detected, locate the source of the short-circuit
as follows:
Disconnect the cables that are connected to
the CU/PU board one cable after another until
location of the short-circuit is found out.
Action to be taken
at NG
Supply the AC
power.
Set the low
voltage power
supply setting.
Replace the low
voltage power
supply.
Replace F2
or the CU/PU
board.
Replace the part
causing short-
circuit.
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