64
MEP-7000
1
2
3
4
A
B
C
D
E
F
1
2
3
4
If the problem is not resolved even
after the above-mentioned
measures are taken.
Check if the voltage (2.2-2.7 V) in
the normal direction is supplied to
the two electrodes of the LED.
Check that the signal for the LED
is output from the CE
N
TER PA
N
EL
microcomputer (IC
8
00).
Lighting of the LEDs on the DISP
Assy is dynamically controlled in
matrix. Referring to the circuit
diagram, check if the LED that
does not light belongs to any
matrix group.
Check the LED drive signal that is
input from the SIDE PA
N
EL
microcomputer (IC2600) to the
transistor for the matrix group of an
LED that does not light.
If a signal is input, the transistor is defective;
replace it. If no signal is input, check the
mounting status of the SIDE PA
N
EL microcom-
puter (IC2600). If it is properly mounted, the port
connector may be defective; replace it.
If the LED does not belong to a matrix group,
that LED is defective; replace it. If the LED
belongs to a matrix group, the drive signal for
the group of that LED is defective. Go to [2].
If the voltage in the normal direction is supplied,
the LED is defective; replace it. If there is no
voltage in the normal direction, go to [2].
If no signal is output, check the mounting status
of the CE
N
TER PA
N
EL microcomputer (IC
8
00).
If it is properly mounted, the port connector may
be defective; replace it.
The transistor is defective; replace it.
No.
Waveform
Items for check
Causes and measures
Points to be checked
1
-
2
3
-
1
-
2
Any one of the LEDs on the center area does not light.
N
MAI
N
ASSY/
RE
N
C ASSY
N
MAI
N
ASSY/
RE
N
C ASSY
N
MAI
N
ASSY/
RE
N
C ASSY
DISP ASSY
DISP ASSY
See the
circuit
diagram.
Any one of the LEDs on the DISP Assy does not light.
1
-
1
-
2
-
1
1
2
All the keys for the Controller A/B do not function.
Any one of the keys for the Controller A/B does not function.
N
MAI
N
ASSY
DISP ASSY
-
CABLE
N
MAI
N
ASSY
DISP ASSY
152,
153
-
-
Any one of the keys on the center area does not function.
All the keys on the RE
N
C Assy do not function.
No.
Waveform
Items for check
Causes and measures
Points to be checked
[3-9] LEDs not lit
Check if the FFC that connect the
N
MAI
N
and RE
N
C Assys are
securely connected and if there is
breakage in the FFC.
Check if there is poor connection
on the signal line from the
CE
N
TER PA
N
EL microcomputer
(IC
8
00) to the S
W
.
If the problem is not resolved
even after the above-mentioned
measures are taken.
Check the status with the auto
device diagnosis or the status
LEDs.
Check if there is poor connection
on the signal line from the SIDE
PA
N
EL microcomputer (IC2600)
to the S
W
.
If the problem is not resolved
even after the above-mentioned
measures are taken.
If a connection is loose, firmly connect the
cables.
If there is breakage, replace the FFC.
If there is no poor connection from the
CE
N
TER PA
N
EL microcomputer (IC
8
00) to
the S
W
, the S
W
is defective; replace it.
Check the mounting status of the CE
N
TER
PA
N
EL microcomputer (IC
8
00). If it is properly
mounted, the port connector may be defective;
replace it.
If the SIDE PA
N
EL microcomputer (IC2600) is
judged as
N
G, it has not been correctly started
up. See “[
8
] Auto Device Diagnosis/Status
LEDs” in this section.
If there is no poor connection from the SIDE
PA
N
EL microcomputer (IC
8
00) to the S
W
, the
S
W
is defective; replace it.
Check the mounting status of the SIDE PA
N
EL
microcomputer (IC2600). If it is properly
mounted, the port connector may be defective;
replace it.
See
the circuit
diagram.
