LG 26LC7D (CHASSIS:LB73A) Service Manual ▷ View online
- 17 -
3. When sound is abnormal
(1) Symptom
1) LED is green.
2) Screen display but sound is not output.
2) Screen display but sound is not output.
(2) Check following
Is the SPK cable
normal?
Is the SPK cable
connected well?
Cable inserts well.
No
No
Is the Flat cable
connected well?
Is the RF(Digital)
sound normal?
Cable inserts well.
No
No
Replace the IC200.
Replace SPK cable.
Yes
Yes
Yes
Is the RF(Analog) / AV/
Component L-R sound
normal?
Is the CS5330A(IC1000),
MC33078(IC1001),
Scaler(IC401) normal?
No
No
Is the MSP4450K
(IC200) normal?
Replace the IC400.
Yes
Is the NSP2100
(IC400) normal?
Replace the IC402.
Yes
Is the TAS5122
(IC402) normal?
Replace the IC400.
Yes
Yes
No
No
No
No
Is the Scaler
(IC401) normal?
Replace
VSC Digital B/D.
Yes
Yes
Replace the IC.
No
Is the SPDIF sound
normal?
Is the XC95288(IC300),
CS8415A(IC1003),
Scaler(IC401) normal?
No
Replace the IC.
BLOCK DIAGRAM
- 18 -
HD2_DAC_LRCLK
HD2_ICE958_IN
HD2_DAC_SCLK
H
Y
57
V
1
61
61
0
SI
F
MS
P
4450
PA
L
Tu
n
e
r
(T
A
U
M
-W
1
0
1
P
)
CO
FDM
D
E
M
.+
DV
B
T
u
n
e
r
(T
D
F
B-
Z
2
0
5
P
)
CV
B
S
Y,
C
IIC4
IIC1
99
D
a
ta
[0
:7
],
V
H
_
T
P
_
C
L
K
VA
L
ID
EE
P
R
O
M
(A
T
2
4
C
5
1
2
)
IIC2
SD
R
A
M
(
4
E
A
)
(H
Y
5
7
V
64
16
20
B
)
SD
R
A
M
(
4
E
A
)
(H
Y
5
7
V
64
16
20
B
)
Si
d
e
A
V
V,
L
R
3
Si
d
e
A
V
V,
L
R
33
Re
a
r A
V
V,
L
R
3
Re
a
r A
V
V,
L
R
33
Re
a
r S
YC
2
Re
a
r S
YC
22
MN
T_
O
u
t
V
1
V
11
MS
P
4
4
5
0
Ex
t A
L
R
22
TP/
D
1
99
YC
b
C
r
H,
V
,C
L
K
FI
D
30
YC
b
C
r
2020
H,
V
,C
L
K
33
Y/
U
/
V
IIC3
Re
s
e
t
1010
T
P
[0
:7
],
TP
_
C
L
K
,
TP
_
v
a
li
d
CP
U
A
R
M
(S
3
C
4
4
B0
X
)
X-t
a
l
(1
0
M
)
I2
C
H
u
b
(P
C
A
95
16
)
IIC1
IIC2
IIC3
IIC4
IIC1
IIC2
IIC3
IIC4
IIC1
IIC2
IIC3
IIC4
KI
A
7
0
2
9
74
H
C
1
4D
Re
s
e
t
SD
R
A
M
(
2
EA
)
(H
Y
5
7
V
64
16
20
B
)
SD
R
A
M
(
2
EA
)
(H
Y
5
7
V
64
16
20
B
)
FLAS
H
(
2
E
A
)
(A
T
49B
V
1
60)
FLAS
H
(
2
E
A
)
(A
T
49B
V
1
60)
A/
V
S
W
(C
X
A
2069Q
)
V1
SU
B
(V
/
Y
O
U
T
2
)
VO
U
T
3
OU
T
1
Y1
/
C
1
IN3
HD
-
2
.4
-T
P
D
e-
M
u
x
-M
P
E
G
D
e
c
o
d
in
g
:
MP
@H
L
-F
o
rm
a
t C
o
n
v
e
rt
e
r
-H
o
s
t I/
F
,
M
e
m
o
ry
I/
F
-D
ig
it
al
I
/
F
-Vi
d
e
o
D
A
C
,
N
T
S
C
En
c
o
d
e
r
-A
C
-3
D
e
c
o
d
e
r/
SPD
IF
In
/
o
u
t
-I
E
P
2
SP
D
IF
Ou
t
SPD
IF
In
SPD
I
FO
ut
SD
R
A
M
I
/
F
Te
x
t
De
c
o
d
e
r
(S
D
A
6
001
)
EP
L
D
1
(X
C
9
51
44
X
L
)
C
o
n
tr
o
l GP
IO
Pe
ri
p
h
e
ra
l
Bu
s
S
P
ID
IF
_
IN
_
B
Y
PASS
88
2
RX
[
0
:2
]–
,RX
C
–
DD
C(
I2
C)
EEP
R
O
M
(A
T
2
4C
02N
)
33
YC
b
C
r
Vi
d
e
o
S
W
(C
X
A
2181Q
)
RG
B
-D
T
V
/-
P
C
5
RG
B
H
V
Co
m
p
_
1
YC
b
C
r
33
Co
m
p
_
2
YC
b
C
r
33
EP
L
D
1
(X
C
95144X
L
)
DV
I_
H
,V
,DE
FID
33
OR
3
IIC3
SI
F
PA
L
Tu
n
e
r
Ex
t A
L/
R
22
C
X
A
2069
Co
m
p
_
1
22
L/
R
Co
m
p
_
2
22
L/
R
So
u
n
d
Pr
o
c
(M
S
P
4450)
I2
S
Ou
t
33
HD
-I
I
HD
-I
I
I2
S
_
In
MN
T_
O
u
t
L/
R
22
RG
B
(P
h
o
n
e
)
22
L/
R
Au
d
io AD
C
(C
S
5331)
PW
M
MOD
U
LA
T
O
R
(N
S
P
2100A
)
I2
S
PWM
A
M
P
(T
A
S
5122)
PWM
A
M
P
(T
A
S
5122)
)
OR
1
OR
2
OR
3
3
OR
4
VC
X
O
27
M
h
z
LG
D
P
L
L
(L
G
D
T
1
90
1B)
HD
2
_
V
D
P
C
lk
,
H
D
2_
N
T
2
C
L
K
R
S
-232C
(S
T
3
232)
OR
4
HD
-I
I
DV
B
PAL
RF
SP
L
ITTER
HV
,D
E
RG
B
30
3
DO
u
tC
lk
LV
D
S
T
x
.
(T
H
C
63
L
V
D
1
03
)
TX[
0
:4
]–
TX
C
–
12
LV
D
S
WA
F
E
R
E
EPR
O
M
(A
T
2
4C
02N
)
Bu
ff
er
(M
C
3
3
0
7
8)
CLK
11
OR
1
YC
b
C
r
3030
HD
M
I R
X
& A
D
C
(M
S
T
3
3
6
2
M
)
10
-b
it
HDM
I-S
te
reo
1A
+
1
D
Vi
d
e
o
A
/
D
H
Y
57
V
1
61
61
0
EE
P
R
O
M
(C
A
T
2
4
W
C
)
uC
o
m
(M
T
V
4
1
6
M
)
V4
Th
ro
u
g
h
ou
t
MAIN
(V
/
Y
O
U
T
1
)
SPD
IF
R
x
.
(C
S
8
415)
R
X
_
H
DM
I_
S
P
DI
F
II
C
1
X_
ta
l
24
M
h
z
2
DDC(
I2
C
)
2
H/
V
X-t
a
l
(2
4.
576
M)
1
TX
T
_
C
V
B
S
2
IIC2
TX
T
R
/
G
/
B
,
F
B
/H
/V
6
1
1
1
3
Pe
ri
p
h
e
ra
l
(F
M
S
6403
)
33
YC
b
C
r
Y/
U
/
V
3
H/
V
22
H,
V
,CL
K
OR
2
3
IIC4
FI
D
II
C
2
1
FI
D
OR
3
HD2_ICE958_OUT
1
IIC4
IIC2
II
C
2
2
HD2
_
S
Y
S
CL
K
1
EP
L
D
1
(X
C
9
5
288
X
L
)
2
H
D
2
_
S
Y
S
C
LK
,
E
P
LD
_
C
LK
IIC3
II
C
4
1
2
L/
R
S
C
K
/L
R
C
K
/L
R
C
H
3
S
C
K
/L
R
C
K
/L
R
C
H
4
SC
K
/
L
R
C
K
/
LR
C
H
/
M
S
C
K
1
MC
L
K
2
B
SS8
3
Vi
d
e
o
Dec
o
d
e
r
(u
P
D
64
015
)
3D
Y
/
C
S
e
p
a
ra
to
r
MEMO
- 19 -
- 20 -
EXPLODED VIEW
300
301
200
201
532
531
530
120
590
202
581
204
203
205
601
600
430
402
401
403
431
580
520
400
206
521
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