LG 42LB2R (CHASSIS:LP62E) Service Manual ▷ View online
- 25 -
18. No sound
(1) Symptom
1) LED is white
2) Screen is existent, but sound isn’t output.
2) Screen is existent, but sound isn’t output.
(2) Check following
Set on speaker
in menu.
in menu.
Download the EDID data
Replace IC300.
Check the signal
after IC300 refer to
circuit diagram.
after IC300 refer to
circuit diagram.
Check the Tuner In/Out.
Yes
No
No
Yes
All input(mode)
is no sound.
Is the speaker
on in menu?
check the
Speaker cable.
Speaker cable.
No
Yes
Is the speaker
cable normal?
cable normal?
Replace IC400.
Replace IC401.
Replace IC402.
No
Yes
IC400 operate
normally.
No
Yes
IC401 operate
normally.
Replace VSC Board.
No
Yes
IC402 operate
normally.
Yes
No
No
No
No
Only HDMIis no
Sound.
Only
AV input is no
sound.
Yes
Yes
Only RF is no
sound.
Is the output
of IC300(pin52, 53)
normal?
- 26 -
19. HDMI mode
1. Check TV input mode.
(HDMI1 port support HDMI and DVI.
So if you input DVI signal and PC
audio from phone jac, You ca hear
PC audio.)
So if you input DVI signal and PC
audio from phone jac, You ca hear
PC audio.)
2. Unplug and plug HDMI cable.
3. Check HDMI Mute register. (0x68,
3. Check HDMI Mute register. (0x68,
offset 0x37)
4. Check Audio-out channel mute
register (0x68, offset 0x32) is
apprepriately enabled.
apprepriately enabled.
Download EDID data each port.
Check HDMI source.
Change another source or cable.
Change another source or cable.
Replace IC01200
No
No
Yes
Is only video
normal?
Yes
Is only audio
normal?
No
Check TMDS line wave.
(R1215 ~ R1222/ R1226
~ R1233)
~ R1233)
Is wave
continuous?
Normal video
Normal audio?
Yes
1. Check HDMI receiver’s status register.
(0x60, offset 00x6)
- If the value is 0xf or 0x8, it is normal.
- If the value is 0xf or 0x8, it is normal.
2. Check HDCP register.(0x6, offset 0x32)
- Enable bit 6 : HDCP key loaded
- Enable bit 5 : HDCP dicryption active
- Enable bit 4 : HDCP authen, attempted
- Enable bit 5 : HDCP dicryption active
- Enable bit 4 : HDCP authen, attempted
Reset TMDS power down/ on register.
- 0x60, ofste 0x3f, 0xf7 => 0xff
- 0x60, ofste 0x3f, 0xf7 => 0xff
- 27 -
W
ir
e
d IR
RG
B
_
P
C
R
G
B_
DT
V
PC
_
A
u
d
io
TV
(R
F
)
CO
M
P
AV
3
(R
ear A
V
)
Va
ri
a
b
le
A
u
d
io_
out
AV
1
(S
cart
1
)
(T
V_
o
u
t)
AV
2
(S
cart
2
)
(M
NT
_
O
UT
)
H
D
M
I1
/2
(PC
/D
T
V)
R
S
232
HDM
I_
II
S
V
a
ri
a
b
le
_
a
udio_
out
L
/R
:
500mV
rm
s
TX
232C
D
ri
ver
S
T
3232C
T
x
/R
x :
+
15V
p
p
7
4
HC1
4
D
S
UB
_S
CL
/
D
S
BU
_S
DA
DS
_
V
S
/
DS
_
H
S
P
C
_A
u
d
io
_L
/R
:
700mV
rms
P
C
_A
u
d
io
_L
/R
S I
F
AM
_
A
u
d
io
A
M
_
A
u
d
io
/ S
I
F
MN
T
_
O
U
T
:
1
V
pp
C
O
M
P
1
,2
_
R
IN
/L
IN
TV
_
L
/R
O
U
T
VI
N
4
:
1/
0.
285V
p
p
LIN
4
/R
IN
4
:
500mV
rms
D
DRR
A
M
(128M
B
X
2
)
K
4
D
261638F
-L
C
50X
2
Fla
s
h
-R
OM
(2
M
B
)
A
T
49B
V
160C
L_SPK_OUT
R_SPK_OUT
EE
P
R
O
M
24C
02
V
a
ri
a
b
le
_
a
udio_
out
L
/R
S
C
AR
T
2_I
D
C
o
m
p
_
L
/R
:
500mV
rm
s
T
UNE
R
VI
N
3
:
1/
0.
285V
p
p
S
C
AR
T
1_I
D
A
V
1_V
IN
:
1V
p
p
S
C
A
R
T
1
_
L
IN
/R
IN
:
500mV
rm
s
S
C
AR
T
2_I
D
S
C
A
R
T
2
_
L
IN
/R
IN
:
500mV
rm
s
A
udi
o
S
/W
& CO
NT
RO
L
M
S
P
4
4
50K
SC
A
R
T
1
_
F
B
S
C
AR
T
1_I
D
LIN
3
/R
IN
3
:
500mV
rms
A
V
4_S
W
PW
M
N
T
P
3000H
AM
P
T
A
S
5122
MN
T_
O
U
T
M
N
T
_
LO
U
T
/RO
UT
S
C
A
R
T
2
_
V
IN
/Y
IN
/C
IN
:
1/
0.
285V
p
p
M
N
T_
LO
U
T
/R
OU
T
:
500mV
rms
AV
4
(Si
d
e
A
V
)
MA
IN
S
C
A
L
E
R
F
L
I8662
T
X
D /RX
D :
5V D
ig
ital
VG
A
_
R
G
B
:
0.
7Vp
p
CO
M
P
_
Y
/P
b/P
r
:
1/
0.
7Vp
p
A
IP
_
R
A
W
_
VS /
A
IP_R
A
W
_
H
S
_C
S :
5
V
High/L
ow
SC
A
R
T
1_R
GB
:
0.
7Vp
p
IR
CN_IIS
MC_IIS
HDM
I_
DA
TA
:
3.
3V
HDM
I_
CLK/
DE
:
3.
3V
HDM
I_
IIS
:
3.
3V
HDM
I_
V
S
/HS
:
3.
3V
S
C
L/S
D
A
EE
P
R
O
M
24C
02
HD
M
I Rx
SC
L
/S
D
A
_
Pa
rt
SC
L
/S
D
A
_
Pa
rt
FR
C
E
V
E
N
_R
/G
/B
_D
at
a
-24
D
C
L
K
/D
E/
D
H
S/
D
V
S
F
R
C_
S
D
A/
S
C
L
F
R
C
_
R
eset
_N
E
G
F
R
C_
RX
/T
X
RAM
_
CAS
/R
AS
RAM
_
C
S
/W
E
R
A
M
_
C
K
E
/C
LK
RAM
_
L
DQ
S
/U
D
Q
S
RAM
_
BA0
/1
R
A
M
A
_0~
11
RAM
DQ
S
_
0
~
1
5
FRC_R/G/B_Out_
0
~
9
FRC_DEN/CLK_Out
FRC_HS/VS_Out
Memory
RAM
_
CAS
/R
AS
RAM
_
C
S
/W
E
R
A
M
_
C
K
E
/C
LK
RAM
_
L
DQ
S
/U
D
Q
S
RAM
_
BA0
/1
R
A
M
A
_0~
11
RAM
DQ
S
_
0
~
1
5
LV
D
S
T
x
LV
D
S
_
R
F
_
E
V
E
N
LV
D
S
_
S
W
IN
G
L
V
D
S
_P
W
R
_D
O
W
N
OUT_TX_ CLK
OUT_TX_ E
FRC_R/G/B_Out_
0
~
9
FRC_DEN/CLK_Out
FRC_HS/VS_Out
OUT_TX_ D
OUT_TX_ C
OUT_TX_ B
OUT_TX_ A
EVEN
_R
/G
/B
_D
ata
-24
DCLK
/DE
/DHS
/DV
S
FRC_
S
D
A
/S
C
L
FRC_
R
eset_N
EG
FRC_
R
X
/T
X
S
C
A
R
T
2
_
V
IN/Y
IN/CIN
HDM
I_
DA
TA
HDM
I_
CLK/
DE
HDM
I_
IIS
HDM
I_
V
S
/HS
TU
_
M
AI
N
AV
4
_SW
VIN
4
LIN
4
/RIN
4
S I
F
A
M
_
A
udio
S
C
A
R
T
1
,2
_
LIN/RIN
CO
M
P
_
Y
/P
b
/P
r
:
1/
0.
7V
p
p
S
C
AR
T
1_RG
B
:
0.
7V
p
p
V
IN3
LIN3
/RIN3
A
V
1_VI
N
S
C
A
R
T
2
_
ID
S
C
A
R
T
1
_
FB
S
C
A
R
T
1
_
ID
T
V
_
L/R O
U
T
S
C
A
R
T
1
,2
/A
V
_
LO
U
T
/RO
UT
HDM
I_
IIS
P
C
_
A
udio_
L/
R
A
M
_
A
udio / S
I F
CO
M
P
1
,2
_
RIN/LIN
A
V
_
L
O
U
T
/RO
UT
L_CH
R_CH
L_CH
R_CH
L_OUT
R_OUT
LV
D
S
c
o
nne
c
tor
TV
_
O
U
T
TV
_
O
U
T
SCL/SDA_Part
SCL/SDA_Part
SCL/SDA_Part
SC
L
/S
D
A
_
Pa
rt
SC
L
/S
D
A
_
Pa
rt
_
5
V
SCL/SDA_Part_5V
S
C
L
/S
DA
_P
art
S
C
L
/S
DA
_P
art
S
C
L
/S
DA
_P
art
_5V
S
C
L
/S
DA
_P
art
_5V
TV
_
L
/R
O
U
T
:
500mV
rm
s
F
R
C
_
- 28 -
EXPLODED VIEW
300
200
521
570
121
123
600
120
530
590
122
523
580
520
522
430
400
433
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