Oki Data CONFIDENTIAL
44871001TH Rev.6
8-39
8. TROUBLESHOOTING PROCEDURES
8.5.5.(1) LCD Display Trouble
(1-1) LCD displays nothing
Check item
Checking
Action in case of fail
(1-1-1) Checking fuse
Fuse on SU board (MHE)
Check whether F1 or F5 has
blown.
Replace F1 or F5 or SU
board (MHE).
(1-1-2) Checking connections
Connection between low-
voltage power supply unit and
SU board (MHE)
Make sure the low-voltage power
supply unit is connected to the
POWER connector on the SU
board (MHE) properly.
Check whether the cable
connector is half-connected
or tilted, or whether wires are
broken.
Check whether there is any
fault in the cable assembly, e.g.,
missing wires.
Connect the cable
properly.
Cable assembly connecting
low-voltage power supply unit
to SU board (MHE)
Replace the cable with
a good cable.
Connection between SU
board (MHE) and operation
panel
Make sure the 16-pin FFC is
connected to the OPE connector
on the SU board (MHE) properly.
Make sure the 16-pin FFC is
connected to the CN1 connector
on the OPE board (OPM)
properly.
Check whether the cable
connector is half-connected or
tilted.
Connect the cable
properly.
FFC connecting SU board
(MHE) to OPE board (OPM)
Check for broken wires using a
tester.
Check visually whether the
sheath peels.
Replace the cable with
a good cable.
Check item
Checking
Action in case of fail
(1-1-2) Checking connections
Connection between SU
board (MHE) and CU/PU
board
Make sure the 10-pin FFC
is connected to the GDIIF
connector on the SU board (MHE)
properly.
Make sure the 10-pin FFC
is connected to the MFPIF
connector on the CU/PU board
(98M) properly.
Check whether the cable
connector is half-connected or
tilted.
Connect the cable
properly.
FFC connecting SU board
(MHE) to CU/PU board (98M)
Check for broken wires using a
tester.
Check visually whether the
sheath peels.
Replace the cable with
a good cable
(1-1-3) Checking power supplies
AC power supplied to the
printer
Check the supplied voltage from
the AC power source.
Supply AC power.
5V power supplied to SU
board (MHE)
Check the 5V power at 3, 4pin of
the POWER connector on the SU
board (MHE).
Replace the low-voltage
power supply.
3.3V power supplied to OPE
board (OPM)
Check the 3.3V power at 14pin of
the CN1 connector on the OPE
board (OPM).
Replace the SU board
(MHE).
(1-1-4) Checking for short circuit of power supply
5V and 24V power supplied to
SU board (MHE)
Check for a short circuit using
the POWER connector on the SU
board (MHE).
7, 8pin: 24V
3, 4pin: 5V
5, 6pin: 0VL
9, 10pin: 0VP
If there is a short circuit, locate it.
Disconnect the cables from the
SU board (MHE) one by one to
locate the short circuit.
Replace the short-
circuited component.
Summary of Contents for MB461MFP
Page 1: ...MB461 MB471 MB491 MB491 MB491 LP MPS4200mb MPS4700mb Maintenance Manual 031314C ...
Page 72: ...Oki Data CONFIDENTIAL 44871001TH Rev 6 3 21 3 MFP INSTALLATION Sample MB471 Sample MB491 ...
Page 114: ...44871001TH Rev 6 4 36 Oki Data CONFIDENTIAL 4 REPLACEMENT OF PARTS ...
Page 138: ...Oki Data CONFIDENTIAL 5 LUBRICATING POINT 5 1 Lubrication point 5 2 ...