Oki C711 User Manual

44205401TH Rev.1
151 /
Oki Data CONFIDENTIAL
7. Troubleshooting and repair procedure
7.5.2. (1) LCD display error
Memo For the numbers from
through after name of the respective connectors,
refer to section 7.5.2 (19) "Wiring diagram".
(1-1) LCD does not display anything.
Check item Check work
Action to be taken
at NG
(1-1-1) Check the fuse.
F3,F5 (fuse) of the
CU/PU board
Check if F3,F5 has blown out or not. Replace CU/PU
board.
(1-1-2) Check the system connection
Connection between
the low voltage
power supply unit
and the CU/PU
board.
Check if the cable from the low voltage power
supply to the POWER connector
of the CU/
PU board is normally connected or not.
Check if the connector is connected only in the
half-way or not, and check if the connector is
inserted in slanted angle or not.
Re-connect the
cable normally.
Cable assembly
connecting the low
voltage power supply
unit and the CU/PU
board.
Check if the cable is half-open circuit.
Check if sheath of the cable has not peeled off
or not.
Check if the cable assembly is defective such as
internal wires are disconnected or not.
Replace the
cable with the
normal cable.
Note!
Connection between
the CU/PU board
and Operator Panel
Check if the 11-conductor FFC is connected
to the OPE connector
of the CU/PU board
normally or not.
Check if the 11-conductor FFC is connected
to the OPE connector of the CU/PU board
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.
Re-connect the
cable normally.
FFC connecting the
CU/PU board and
the Operator Panel
board
Check if the cab
le has open circuit or not with
VOM. Check if sheath of the cable has not
peeled off or not by visual inspection.
Replace the FFC
with the normal
FFC.
Check item Check work
Action to be taken
at NG
(1-1-3) Check the peripherals of the power supplies
Primary A
C power
source that is
connected to the
printer.
Check the supplied voltage of the AC power
source.
Supply the AC
power.
Voltage setting of
the lower voltage
power supply unit
(100V system/230V
system)
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.
Set the low
voltage po
wer
supply setting.
5V power that is
supplied to the CU/
PU board.
Check for the 5V po
wer supply at pin-1, 2, 3 of
the POWER connector of the CU/PU board.
Replace the low
voltage power
supply.
3.3V power that
is supplied to the
Operator Panel.
Check for the 3.3V power supply at pin-11 of the
CN connector
of the Operator Panel board.
Replace F2
or the CU/PU
board.
(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.
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.
Replace the part
causing short-
circuit.

Oki C711 Specifications

General

Brand	Oki
Model	C711
Category	Printer
Language	English