LG 42LG70YD (CHASSIS:LJ83A) Service Manual ▷ View online
- 29 -
Check video output
Follow procedure All source audio trouble
shooting
Y
Follow procedure digital TV video
trouble shooting
N
N
Maybe BCM3553(2) internal audio DSP
has problems. Replace it
Check video output
Follow procedure All source audio trouble
shooting
Y
Follow procedure analog TV video
trouble shooting
N
N
Maybe BCM3553(2) audio block has
problems. Replace it
Check L817 voltage level 5V
Replace it
N
Y
Check SIF signal
C801 / C806 / Q800
Replace it
N
Y
Check SIF signal
R652 / C665
Replace it
N
Y
10. Digital TV Audio
11. Analog TV Audio
- 30 -
Check video output
Y
Follow procedure external
input video trouble shooting
N
Check Connector
JK700 / JK702 (Component)
JK703 (RGB)
J701 / JK707 (AV Rear, AV Side)
Replace connector
N
Y
Check signal
C734 / R746 / C735 / R752 (Component1)
C736 / R748 / C737/ R755 (Component2)
C733 / R761 / C760/ R762 (RGB)
C701 / R737 / C700 / R738 (AV Rear)
C726 / R733 / C727 / R795 (AV Side)
Replace it
N
Y
Check CS5345(IC502) power
+3.3V, +5V
Replace it
N
Y
Check CS5345(IC502)
I2S OUTPUT signal
Replace it or IC502
N
Y
Check Audio clock
R134
Replace it
N
Y
Maybe BCM3553(2)(IC100) has
problems
12. Component/ RGB/ AV Audio
- 31 -
Check video output
Follow procedure All source audio trouble
shooting
Y
Follow procedure HDMI video trouble
shooting
N
N
Maybe BCM3553(2)(IC100) audio block
has problems. Replace it
Check EDID NVRAM (IC700, 603, 604)
Power & I2C Signal (#5, #6)
Replace it or redownload
Y
N
Check USB 2.0 Cable
Check L205 voltage level 5V
Y
N
Replace it or IC202
Check P201
Replace it
Y
N
Check USB Device
If device is 2.5 inch HDD, check power adaptor
Y
Maybe BCM3553(2) (IC100)
has problems
Y
• Exception
- USB power could be disabled by inrushing current
- In this case, remove the device and try to reboot the TV (AC power off/on)
13. HDMI Audio
14. USB
- 32 -
BLOCK DIAGRAM
Fl
a
s
h
(32M
B
)
C
S
5345
Au
d
io
SW
MT
V
4
1
6
(M
ic
o
m
)
N
T
P
3000
(D
ig
it
a
l A
M
P
)
64B
it
I/
F
RG
B
-P
C
HD
M
I
1/
2/
3
COM
P
1
COM
P
2
AV
1
AV
2
RG
B
-P
C
I2
S
MC
LK
LV
D
S
COM
P
1
COM
P
2
AV
1
AV
2
B
C
M
7412
(M
P
E
G
4
De
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/D
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90512
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IF
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CV
B
S
CV
B
S
/
Y
/
C
Y/
C
b/
C
r
R/
G
/
B
DDR1
(64M
B)
Se
ri
a
l TP
20b
it
s
12b
it
Y
C
4:
2:
2
NI
M
T
U
NE
R
TM
D
S
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+
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A
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ly
)
T
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A
(3
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,S
/
W
)
CV
B
S
/
Y
/
C
R
S
232
RX
/
T
X
DV
I
4:
2:
2
20b
it
Y
C
F
u
ll
H
D
(1080P
)
RF
Sw
it
c
h
RF
Sw
it
c
h
RF
Sw
it
c
h
DM
1
/
DP
1
Se
ri
a
l
TP
7
4
HC0
4
SP
D
IF
O
u
t
(C
o
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x
ia
l)
Vi
d
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o
Fr
o
n
t
En
d
Du
a
l
HD
M
I
Rx
HD
/
S
D
Vi
d
e
o
En
c
o
d
e
r
Au
d
io
DS
P
US
B
2
.0
PK
T
HS
X
PC
I/
EB
I
HD
-D
V
I
IB
0
Pa
rs
e
2
RS
B
U
F
XC
B
U
F
RM
X
0
BC
M
3553
Lo
c
a
l K
E
Y
24
C
1
6
74L
V
C
14A
P
W
X
-t
a
l(
54M
)
Re
s
e
t
K
IA
7
029
NV
R
A
M
I2
C
F
R
C
9459M
(120
H
z
)
DDR
1
(64M
B)
DU
A
L
L
V
DS
Du
a
l L
V
DS
WA
F
E
R
(40P
)
Du
a
l L
V
DS
WA
F
E
R
(26P
)
DDR1(128MB)
(16Mx16x4)
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