DOWNLOAD LG 19LN4050 (CHASSIS:LB35A) Service Manual ↓ Size: 4.97 MB | Pages: 28 in PDF or view online for FREE

Model
19LN4050 (CHASSIS:LB35A)
Pages
28
Size
4.97 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / LCD
File
19ln4050-chassis-lb35a.pdf
Date

LG 19LN4050 (CHASSIS:LB35A) Service Manual ▷ View online

- 16 -
7. Abnormal sound (TV)-Main PCBA
Put into RF cable completely?
Abnormal sound (TV)
YES
NO
insult RF cable tight and then 
Cable nut screw tight.
1
2
3
4
NO
Change Main PCBA
WAVEFORMS
Is 1.8V at 7pin of TU401?
Is I2C waveform 
At 3,4pin of TU401?
Is IF waveform at 43
,44 pin of IC501?
NO
NO
3
3Pin of TU401 (SCL)
4Pin of TU401 (SDA)
4
43,44pin of IC501
If 1.7V is not at plus pin of TU401,
check It is over 3V at 2pin of IC401, 
if it is not, Check Line between TU401 
and IC401 is open or short.
Another is change IC401 or TU401
Check Line between TU401 and IC501
is open or short,  Another is change 
IC501 or TU401
Check Line between TU401 and IC501
is open or short,  Another is change 
IC501 or TU401
- 17 -
8. Abnormal sound (AV)-Main PCBA
wœ›G•›–Gh}GŠˆ‰“ŒGŠ–”—“Œ›Œ“ f
Abnormal sound (AV)
YES
NO
Insult AV cable tight
1
Change IC501
WAVEFORMS
pšGžˆŒ–™”G ˆ›Gj\YWSj\YX
2
Check Line between JK101 and IC501
is open or short,  Another is 
change AV cable
NO
YES
j\YWSj\YXOˆœ‹–G •P
2
- 18 -
Ad
ap
to
r
S
ou
nd
 A
M
P
N
TP
75
13
(
(
(
(
Mo
du
le
Au
di
o
O
ut
M
ST
68
41
XP
5
9
4
3
10
11
Tu
ne
r SD
A
Tu
ne
r SC
L
TU
N
E
R
IF
_A
G
C
B+
IR
/K
EY
40
24
M
hz
98
99
44
43
IC
5
0
2
Se
ria
l F
la
sh
8M
by
te
s
IC
5
0
3
EE
PR
O
M
24
C
64
30
LP
F
33
18
21
O
P-
A
M
P
x4
 G
ai
n
Aud
io 
L-O
ut
X
X
X
39
37
38
Aud
io 
R-O
ut
H
D
M
I
SC
L/
SD
A
48
115
50
51
113
11
2
A
ud
io
_S
C
L
A
ud
io
_S
D
A
LV
D
S
O
ut
pu
t
P D
im
Inv
. O
N
P
_S
3.
5V
M
_3
.3
V
TU
_3
.3
V
19V
M
ai
n_
1.
2V
+1
8V
10
11
7
8
9
38
I2
S_
M
C
LK
I2
S_
W
S
I2
S_
SC
K
I2
S_
SD
O
10
8
11
1
11
7
IR
KEY
1
Led
_PW
R
10
2
105
53
52
45
85
84
EE
SD
A
EE
SC
L
94
95
97
96
SP
I_
C
LK
SP
I_
D
I
SP
I_
C
Z
SP
I_
D
O
S_
A
M
P_
19
V
32
40
LP
F
U
SB
_5
V
110
KEY
2
ST
_3
.5
V
P_
12
V
Q
71
0
M
ai
n_
1.
8V
M
_3
.3
V
Q
72
0
A
O
34
07
A
Pa
ne
l_
Vc
c
M
ai
n_
5V
To
 U
SB
U
SB
_D
N
U
SB
_D
P
IF_
P
IF_
N
31
35
1.
8V
 R
EG
7
TU
_1
.8
V
19
20
Aud
io 
out
27,35,3
6
22,20,24,
77
62
54
41
30
18
9
116
10
7
10
0
101
Led
_PW
R
D
T1
64
1S
TP
S4
02
10
M
od
ul
e
B
LU
ĝ
ĝ
LE
D
_2
8V
B
LU
_2
4V
M
od
ul
e
B
LU 
ĝ
M
P2
00
51
1.
8V
 R
EG
M
P1
47
2
M
P1
58
4
M
P1
47
2
+1
8V
Q
71
2
To
 
O
P_
A
M
P
CVB
S In
AV 
aud
io 
in
BLOCK DIAGRAM
- 19 -
A2
A31
900
200
400
540
402
401
910
120
122
300
510
502
51
1
501
800
801
LV
1
EXPLODED VIEW
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These 
parts are identified by       in the Schematic Diagram and EXPLODED VIEW. 
It  is  essential  that  these  special  safety  parts  should  be  replaced  with  the  same  components  as 
recommended in this manual to prevent X-RADIATION, Shock, Fire, or other Hazards. 
Do not modify the original design without permission of manufacturer.
IMPORTANT SAFETY NOTICE
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