LG 32LC4D (CHASSIS:LT73A) Service Manual ▷ View online
- 17 -
14. No Sound
(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 there sound
in an mode?
Is the speaker
on?
Yes
Yes
Is the speaker
cable normal?
cable normal?
Yes
Yes
Is there no sound
only for HDMI?
Yes
Is there no sound
only for RF?
Check the Tuner
IN/OUT
Yes
Is there
no sound only for
AV/component/PC
input?
No
No
No
No
Download the EDID data.
Set on speaker
in menu.
in menu.
No
Check the Speaker
cable.
cable.
No
Is the IC1300
operating normal?
Replace IC1300.
(MSP4450)
(MSP4450)
No
Yes
Is the IC1301
operating normal?
Replace IC1301.
(STA335BW)
(STA335BW)
Replace VSC B/D.
Is the output of
CXA2069 normal?
CXA2069 normal?
No
Check the siganl before
CXA2069 refer to circuit
diagram
CXA2069 refer to circuit
diagram
Check the signal after CXA2069.
Refer to circuit diagram.
Refer to circuit diagram.
No
Replace CXA2069
No
Yes
Is there
no sound Only for
specific input (except
HDMI, DTV,
RF)?
Yes
BLOCK DIAGRAM
- 18 -
ST
I
5
1
0
0
G
FL
I
8
5
4
8
CX
A
2
0
6
9
Q
TDFB- T102P
1
SDRAM
256Mbi t
Fl as h memor y
32Mbi t
MSP4450K
STA335BW
F
l
a
s
h
m
em
or
y
32
M
b
i
t
SDRAM
256Mbi t
S
T
D
M
I
0
02A
HDM
I
SW
IT
C
H
AM
_
A
U
D
I
O
AV_
L
R
O
U
T
S- VI DEO
AV1 CVBS
AV1 LR
TUNER CVBS
PC SOUND
MN
T
_
L
R
O
U
T
M
N
T
_
V
I
D
E
O
O
U
T
(
C
V
BS)
COMP1 YPbPr
COMP2 YPbPr
RGBHV
TM
D
S
CO
M
P
2
L
R
CO
M
P
1
L
R
I2
S
SP
K
DI
G
I
T
A
L
T
S
656
d
a
t
a
LCD PANLE
PDP PANLE
LV
D
S
I2
C
I2
S
SW
IT
C
H
I2
S
DTV I 2S / SPDI F
HDMI I 2S / SPDI F
SPDI F OUT
ST
I
5
1
0
0
G
FL
I
8
5
4
8
CX
A
2
0
6
9
Q
TDFB- T102P
1
1
SDRAM
256Mbi t
SDRAM
256Mbi t
Fl as h memor y
32Mbi t
Fl as h memor y
32Mbi t
MSP4450K
MSP4450K
STA335BW
STA335BW
F
l
a
s
h
m
em
or
y
32
M
b
i
t
F
l
a
s
h
m
em
or
y
32
M
b
i
t
SDRAM
256Mbi t
SDRAM
256Mbi t
S
T
D
M
I
0
02A
HDM
I
SW
IT
C
H
AM
_
A
U
D
I
O
AV_
L
R
O
U
T
S- VI DEO
AV1 CVBS
AV1 LR
TUNER CVBS
PC SOUND
MN
T
_
L
R
O
U
T
M
N
T
_
V
I
D
E
O
O
U
T
(
C
V
BS)
COMP1 YPbPr
COMP2 YPbPr
RGBHV
TM
D
S
CO
M
P
2
L
R
CO
M
P
1
L
R
I2
S
SP
K
DI
G
I
T
A
L
T
S
656
d
a
t
a
LCD PANLE
PDP PANLE
LV
D
S
I2
C
I2
S
SW
IT
C
H
I2
S
DTV I 2S / SPDI F
HDMI I 2S / SPDI F
SPDI F OUT
TAUV- H30
TAUV- 30
TAUV-
0
- 19 -
ST
I
5
1
0
0
G
FL
I
8
5
4
8
CX
A
2
0
6
9
Q
TDFB- T102P
‘ TAUV- H301P
SDRAM
256Mbi t
Fl as h memor y
32Mbi t
MSP4450K
STA335BW
F
l
a
s
h
m
em
or
y
32
M
b
i
t
SDRAM
256Mbi t
S
T
D
M
I
0
02A
HDM
I
SW
IT
C
H
AM
_
A
U
D
I
O
AV_
L
R
O
U
T
S- VI DEO
AV1 CVBS
AV1 LR
TUNER CVBS
PC SOUND
MN
T
_
L
R
O
U
T
M
N
T
_
V
I
D
E
O
O
U
T
(
C
V
BS)
COMP1 YPbPr
COMP2 YPbPr
RGBHV
TM
D
S
CO
M
P
2
L
R
CO
M
P
1
L
R
I2
S
SP
K
DI
G
I
T
A
L
T
S
656
d
a
t
a
LCD PANLE
PDP PANLE
LV
D
S
I2
C
H
I2
S
DTV I 2S / SPDI F
HDMI I 2S / SPDI F
SPDI F OUT
ST
I
5
1
0
0
G
FL
I
8
5
4
8
CX
A
2
0
6
9
Q
TDFB- T102P
‘ TAUV- H301P
‘ TAUV- H301P
SDRAM
256Mbi t
SDRAM
256Mbi t
Fl as h memor y
32Mbi t
Fl as h memor y
32Mbi t
MSP4450K
MSP4450K
STA335BW
STA335BW
F
l
a
s
h
m
em
or
y
32
M
b
i
t
F
l
a
s
h
m
em
or
y
32
M
b
i
t
SDRAM
256Mbi t
SDRAM
256Mbi t
S
T
D
M
I
0
02A
HDM
I
SW
IT
C
H
AM
_
A
U
D
I
O
AV_
L
R
O
U
T
S- VI DEO
AV1 CVBS
AV1 LR
TUNER CVBS
PC SOUND
MN
T
_
L
R
O
U
T
M
N
T
_
V
I
D
E
O
O
U
T
(
C
V
BS)
COMP1 YPbPr
COMP2 YPbPr
RGBHV
TM
D
S
CO
M
P
2
L
R
CO
M
P
1
L
R
I2
S
SP
K
DI
G
I
T
A
L
T
S
656
d
a
t
a
LCD PANLE
PDP PANLE
LV
D
S
I2
C
H
I2
S
DTV I 2S / SPDI F
HDMI I 2S / SPDI F
SPDI F OUT
19.
6
6
0
8
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z
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B
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(H
DCP
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)
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HDM
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PDP PANLE
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C
- 20 -
ST
I
5
1
0
0
G
FL
I
8
5
4
8
CX
A
2
0
6
9
Q
TDFB- T102P
TAUV- H301P
SDRAM
256Mbi t
Fl as h memor y
32Mbi t
MSP4450K
STA335BW
F
l
a
s
h
m
em
or
y
32
M
b
i
t
SDRAM
256Mbi t
S
T
D
M
I
0
02A
HDM
I
SW
IT
C
H
AM
_
A
U
D
I
O
AV_
L
R
O
U
T
S- VI DEO
AV1 CVBS
AV1 LR
TUNER CVBS
PC SOUND
MN
T
_
L
R
O
U
T
M
N
T
_
V
I
D
E
O
O
U
T
(
C
V
BS)
COMP1 YPbPr
COMP2 YPbPr
RGBHV
TM
D
S
CO
M
P
2
L
R
CO
M
P
1
L
R
I2
S
SP
K
DI
G
I
T
A
L
T
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656
d
a
t
a
LCD PANLE
PDP PANLE
LV
D
S
I2
C
I2
S
SW
IT
C
H
I2
S
DTV I 2S / SPDI F
HDMI I 2S / SPDI F
SPDI F OUT
ST
I
5
1
0
0
G
FL
I
8
5
4
8
CX
A
2
0
6
9
Q
TDFB- T102P
TAUV- H301P
TAUV- H301P
SDRAM
256Mbi t
SDRAM
256Mbi t
Fl as h memor y
32Mbi t
Fl as h memor y
32Mbi t
MSP4450K
MSP4450K
STA335BW
STA335BW
F
l
a
s
h
m
em
or
y
32
M
b
i
t
F
l
a
s
h
m
em
or
y
32
M
b
i
t
SDRAM
256Mbi t
SDRAM
256Mbi t
S
T
D
M
I
0
02A
HDM
I
SW
IT
C
H
AM
_
A
U
D
I
O
AV_
L
R
O
U
T
S- VI DEO
AV1 CVBS
AV1 LR
TUNER CVBS
PC SOUND
MN
T
_
L
R
O
U
T
M
N
T
_
V
I
D
E
O
O
U
T
(
C
V
BS)
COMP1 YPbPr
COMP2 YPbPr
RGBHV
TM
D
S
CO
M
P
2
L
R
CO
M
P
1
L
R
I2
S
SP
K
DI
G
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T
A
L
T
S
656
d
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t
a
LCD PANLE
PDP PANLE
LV
D
S
I2
C
I2
S
SW
IT
C
H
I2
S
DTV I 2S / SPDI F
HDMI I 2S / SPDI F
SPDI F OUT
FLI 8548
FLI 8548
F
L
ASH
M
E
M
O
R
Y
32
M
B
I
T
SD
R
A
M
25
6M
B
I
T
656
d
at
a
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PR
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M
I2
C
27M
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z
32.
7
K
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t
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t
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FM
I
W
E(
R
e
a
d
n
o
t
w
r
i
t
e
)
F
M
I
C
S
3
(
C
hi
p
s
e
l
ec
t
)
F
M
I
C
S
1
(
C
hi
p
s
e
l
ec
t
)
F
M
I
B
E
1
(
B
y
t
e
e
n
a
bl
e)
I2
S
SPD
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F
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T
V
C
VBS
DT
V
L
R
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t
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S
da
t
a
BU
F
F
ER
TS
D
A
TA
S
Y
N
C
/
V
A
L
/
C
L
K
BU
F
F
E
R
S
T
I5100
LD
B
A
[
0:
1
]
(
B
ank
S
el
e
c
t
)
LD
D
Q
M
[
0:
1
]
(
D
at
a
I
/
O
M
a
s
k
)
L
D
D
Q
S
[
0
:
1]
(
D
a
t
a
S
t
r
ob
e)
LD
C
S
(
C
hi
p
S
el
e
c
t
)
LD
R
A
S
(
L
a
t
c
h
R
ow
A
d
dr
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s
S
t
r
ob
e)
LD
C
A
S
(
L
a
t
c
h
C
ol
um
n
A
ddr
e
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s
S
t
r
o
b
e)
LD
W
E(
W
ri
t
e
E
n
a
b
l
e
)
L
D
C
L
KE
(
C
l
o
c
k
En
a
b
l
e
)
L
DCL
K
(
C
l
o
c
k
)
LD
C
L
K
N
(
I
nv
er
t
e
d
C
l
o
c
k
)
S
T
I5100
LD
B
A
[
0:
1
]
(
B
ank
S
el
e
c
t
)
LD
D
Q
M
[
0:
1
]
(
D
at
a
I
/
O
M
a
s
k
)
L
D
D
Q
S
[
0
:
1]
(
D
a
t
a
S
t
r
ob
e)
LD
C
S
(
C
hi
p
S
el
e
c
t
)
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R
A
S
(
L
a
t
c
h
R
ow
A
d
dr
es
s
S
t
r
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e)
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C
A
S
(
L
a
t
c
h
C
ol
um
n
A
ddr
e
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s
S
t
r
o
b
e)
LD
W
E(
W
ri
t
e
E
n
a
b
l
e
)
L
D
C
L
KE
(
C
l
o
c
k
En
a
b
l
e
)
L
DCL
K
(
C
l
o
c
k
)
LD
C
L
K
N
(
I
nv
er
t
e
d
C
l
o
c
k
)
TDFB- T102P
TDFB- T102P
I2
C
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