Lcd Display Trouble; Lcd Displays Nothing; Please Wait - Oki C310dn Maintenance Manual

Oki Data CONFIDENTIAL

7.5.2.(1) LCD display trouble

Memo For the numbers 1 to 15 each after the connector names, see 7.5.1 (19)
Connection diagram.

(1-1) LCD displays nothing

Check item
(1-1-1) Fuse check
CU/PU board fuse Check F5 (C530/C330) or F7 (C510/C310) is
not cut.
(1-1-2) Connection-line chec
Connection of low- Check the cord from the low-voltage
voltage power unit power supply to the CU/PU board POWER
and CU/PU board connector is properly connected.
Check for half connection or skew insertion.
Cord assembly Check for breakdown.
connecting low- Check for sheathing removal.
voltage power unit Check for defectiveness of cord assembly,
and CU/PU board such as wire removal.
Connection Check that 12-pin FFC is properly connected
between CU/PU to the CU/PU board OPE connector 17.
board and operator Check that 12-pin FFC is properly connected
panel board to the operator panel board CN1 connector.
Check for half connection or skew insertion.
FFC connecting Check for breakdown with a tester. Visually
CU/PU board and check for sheathing removal.
operator panel
board
(1-1-3) Power supply periphery check
AC power supplied Check the AC power supply voltage.
to printer
5V power supplied Check the 5V power supply by using the
to CU/PU board pins 1, 2 and 3 of the CU/PU board POWER
connector 10.
3.3V power supply Check 3.3V power supply by using the pin 7
to operator panel of the CU/PU board CN1 connector 19.
board
44346001TH Rev.1
Actions for NG
Check operation
results
Replace the
CU/PU board.
Re-insert the
cord properly.
Replace cords
with proper
ones.
Re-insert the
cord properly.
Replace the
FFC with a
proper one.
Supply AC
power.
Replace the low
voltage power
supply.
Replace the
CU/PU board.
Check item
(1-1-4) Power supply short-circuit check
5V and 24V power Check short circuiting by using the CU/PU
supplied to CU/PU board POWER connector 10.
board When the following is found, separate short-
circuited points as described below.
Pins 7, 8 and 9: 24V
Pins 1, 2 and 3: 5V
Pins 4, 5 and 6: 0VL
Pins 10, 11 and 12: 0VP.
Locate short circuits by pulling out the cords
connected to the CU/PU board one by one
(1-1-5) LSI operation check
Interface signals Check that signals are output to the CU/PU
from CU/PU board board OPE connector 17.
to operator panel Pin 6: Transmission data (CY/PU board
board transmission)
Pin 8: CLR
Signals are always output when the above is
proper.
Interface signals
Check that signals are output to the CU/PU
board OPE connector 17.
from operator
Pin 5: Reception data (CU/PU board
board to CU/PU
reception)
board
Signals are always output when the above is
proper.

(1-2) PLEASE WAIT

(The display changes to COMMUNICATION ERROR when printer is left unaccessed)
Check item
(1-2-1) Operator panel display does not change
Operator panel The display COMMUNICATION ERROR
display persists.
7. TROUBLESHOOTING
Actions for NG
Check operation
results
Replace short-
circuited parts.
Replace the
CU/PU board.
Replace the
operator panel
board.
Check operation Actions for NG
results
Replace the
CU/PU board.
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