LG 42LN549C / 42LN549E (CHASSIS:LJ3AC) Service Manual ▷ View online
- 21 -
All Source Audio Trouble Shooting
Make sure you can’t hear any audio
Check 12S Signal
DATA,CLK,L/RCLK
Check IC402 Power 1.8V,3.3V_PRO,
16V
L516,R505,R508
Replace FB
Y
N
Replace it
N
Check Connector
P1200
Y
Y
Replace connector
N
Check speaker
Y
Replace speaker
N
Maybe NTP3000A has problems.
Replace it
Y
- 22 -
Analog TV Audio Trouble Shooting
Check video output
Follow procedure All source audio
trouble shooting
Y
Follow procedure analog TV
video trouble shooting
N
N
Maybe NTP3000A audio block
has problems. Replace it
Check L516 voltage level 16V
Replace it
N
Y
Check I2S signal
Replace it
N
Y
Digital TV Audio Trouble Shooting
Check video output
Follow procedure All source audio
trouble shooting
Y
Follow procedure digital TV
video trouble shooting
N
N
Maybe NTP3000A internal
audio DSP has problems.
Replace it
- 23 -
Component / RGB / AV Audio Trouble Shooting
Check video output
Y
Follow procedure
external input video
trouble shooting
N
Check Connector
JK601 (Component)
JK605 (RGB)
JK600 / JK500
(AV Rear, AV Side)
Replace connector
N
Y
Check signal
R620,R621(Component)
R638,R639(RGB)
R613,R614(AV Rear)
R668,R667(AV Side)
Replace it
N
Y
Check Q711 power voltage
level 16V
Replace it
N
Y
Maybe NTP3000A has
problems
HDMI Audio Trouble Shooting
Check video output
Follow procedure All source audio
trouble shooting
Y
Follow procedure HDMI video
trouble shooting
N
N
Maybe NTP3000A audio block
has problems. Replace it
Check EDID NVRAM (IC800)
Power #8 & I2C Signal (#5, #6)
Replace it or redownload
Y
N
- 24 -
BLOCK DIAGRAM
R
GB
PC
H
D
M
I2
H
D
M
I1
Fu
ll
N
IM
(C
AN
)
R
S-
232
C
Pa
ra
lle
l T
S
TU
_C
VBS
SI
F
S7
LR
M
AX32
32
SER
IA
L
FL
ASH
M
XI
C
(8M
B
IT
)
M
X2
5L
800
6EM
2I
-12
G
LVD
S
80M
H
z
(60
H
z/
/H
D
/F
H
D
)
A.
A
M
P
N
TP75
00
U
SB
2.
0
D
P/
D
M
SPK
L
/R
X
-t
a
l
2
4
M
H
z
51P
I2S
L/
R
TM
D
S
R
GB/
H
/V
R
S232
C
R
ea
r
TM
D
S
D
D
R
2
Ad
d.
D
D
R
2
D
at
a
SPI
AV
Si
de
N
AN
D
F
la
sh
(1
or
2GB
IT
)
PC
M
_A[
0:
7]
TM
D
S
H
D
M
I3
C
VBS,
L/
R
D
D
R
3
1
or
2G
H
yn
ix
H
5T
Q2
G63
B
FR
-H
9C
667M
H
z
30P
IR
ou
t-Pa
th
D
D
R
3
1G
H
yn
ix
H
5T
Q1
G63
D
FR
-H
9C
667M
H
z
14
8.
5M
H
z
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