LG 26LN45XX / 26LN4503 / 26LN450B / 26LN450U / 26LN4573 / 26LN4575 / 26LN457B / 26LN457U (CHASSIS:LC31A / LD31T) Service Manual ▷ View online
- 17 -
4. No Video - Component
Check input signal format
Is it supported?
Check signal
R239,R237,R241
C220,C218,C222
Replace R239,R237,R241
C220,C218,C222
Y
N
Check JK2800
Replace JK2800 or
Check Device
Y
N
Y
IC101 has problem
Y
Check Component Cable
Wave form of C220
Wave form of C218
Wave form of C222
Wave form of Comp Y
Wave form of Comp Pb
Wave form of Comp Pr
5. No Video - RGB
Check input signal format
Is it supported?
Check Hsync, Vsync
R4024, R4025
Replace R4024, R4025
Check signal RGB
R228,R230,R232
C204,C206,C208
N
Check JK400
Replace JK400 or
Check Device
Y
N
Y
Replace R228,R230,R232
C204,C206,C208
N
IC101 has problem
Y
Check RGB Cable
Wave form of R4025(Vsync)
Wave form of R4024(Hsync)
Wave form of R230/C206
Wave form of R228/C204
Wave form of R232/C208
Y
Y
- 18 -
6. No Video - HDMI
Check input signal format
Is it supported?
Y
Check JK500,501
for proper connection or damage
Replace connector
Y
N
Y
Check HDMI Cable for damage
or open connector
Check I2C Signal (JK500,501)
(#15, #16)
Re download EDID data
Y
N
Check HDCP Key (IC101)
Replace Scaler(IC101)
N
7. No Audio
Make sure you can’t hear any audio and
Device support the audio signal normally.
Check Speaker and
its wire connection (P700)
and the resistance
Check Signal from IC700
L700,L701, L706, L709
Y
Replace IC700
N
Check R4045 Voltage Level (3.3V)
Y
Replace IC807(3.3V)
N
Y
Check Signal from IC101
SDA/SCL
(R703/R214, R707/R213)
Y
Replace IC101
N
Replace connector or Speaker
N
- 19 -
LG
E2
12
1-
M
S1
0
(M
SD
80
4K
K
X)
M
st
ar
M
1(
L1
3)
C
O
M
P
O
N
E
N
T
R
S-
23
2C
[O
pt
io
n
: O
nl
y
ho
te
l m
od
el
]
R
G
B
M
AX
32
32
C
D
R
D
SU
B
_R
/G
/B
/H
/V
Au
di
o
IN
H
P
L
&
R
o
ut
C
O
M
P
_Y
,
P
b
,P
r
C
O
M
P
_L
&
R
_I
N
U
SB
(
Jp
eg
,M
P
3,
D
VI
X)
AP
21
91
D
SG
LG
IT
H
AL
F
l N
IM
(D
VB
T
/C
)
SC
AR
T
(F
ul
l)
P
C
M
C
IA
S
lo
t
FE
_T
un
er
_S
D
A&
SC
L
SC
AR
T_
O
U
T
74
LV
C
54
1A
Bu
ffe
r
IC
50
2
FE
_T
S_
C
LK
FE
_T
S_
VA
L
E
rr
or
FE
_T
S_
SY
N
C
FE
_T
S_
D
AT
A
B
uf
fe
r_
FE
_T
S_
C
LK
B
uf
fe
r_
FE
_T
S_
VA
L
E
rr
or
B
uf
fe
r_
FE
_T
S_
SY
N
C
B
uf
fe
r_
FE
_T
S_
D
AT
A[
0]
D
D
R
3
SD
R
AM
2G
B
D
D
R
3
SD
R
AM
(1
G
B
)
N
AN
D
F
la
sh
1G
B
74
LC
X2
44
B
uf
fe
r
IC
50
1
C
I_
C
LK
C
I_
VI
AL
E
rr
or
C
I_
SY
N
C
C
I_
D
AT
A[
0~
7]
C
I A
D
D
R
[0
~7
]
P
C
M
_D
AT
A
[0
~7
]
P
C
M
_A
[0
~7
]
C
I_
AD
D
R
[0
~1
4]
R
E
G
C
I_
O
E
C
I_
IO
R
D
C
I_
IO
W
R
C
I-W
E
P
C
M
_A
[0
~1
4]
FE
_D
E
_S
D
A&
SC
L
SE
R
IA
L
Fl
as
h
C
VB
S&
S
ca
rt
R
G
B
TV
L
&
R
S
ou
nd
F_
R
B
P
F-
O
E
P
F_
C
E
O
SP
I_
C
K
SP
I_
C
I
SP
I_
C
S
SP
I_
D
O
D
D
R
2
D
at
a[
0:
15
]
D
D
R
2
Ad
dr
es
s[
0:
12
]
D
D
R
2
D
at
a[
0:
15
]
D
D
R
2
Ad
dr
es
s[
0:
12
]
Sy
st
em
EE
P
R
O
M
E
E
P
R
O
M
S
C
L
&
S
D
A
Pa
ne
l
D
M
B
[L
E
D
D
riv
er
IC
]
D
ig
ita
l
am
p
(N
TP
75
13
)
SP
(L
)
SP
(R
)
W
LE
D
-S
ta
tu
s
W
LE
D
_E
N
AB
LE
O
VP
_S
E
L
C
H
_S
E
L
W
LE
D
_D
IM
_A
D
J
Au
di
o_
M
as
te
r_
C
LK
/D
AT
A[
3]
LV
D
S
1
C
h
SI
F
-D
VB
-T
/C
:
TD
SS
-G
50
1D
(H
al
f N
IM
)
-A
TS
C
: T
D
SS
-H
50
1F
(H
al
f N
IM
)
-I
SD
B -
T
: T
D
SN
-B
60
1F
(F
ul
l N
IM
)
AM
P
S
C
L&
SD
A
C
VB
S
H
D
M
I_
TM
D
S
&
H
D
M
I
I2
C
D
D
R
3:
80
0M
H
z
H
D
M
I(M
H
L)
H
ea
dp
ho
ne
Option
Option(Only for DVB)
Option
Option(Only for DVB)
BLOCK DIAGRAM
- 20 -
A2
A31
900
200
400
401
540
521
800
910
120
300
501
531
510
51
1
301
122
LV1
801
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
Click on the first or last page to see other 26LN45XX / 26LN4503 / 26LN450B / 26LN450U / 26LN4573 / 26LN4575 / 26LN457B / 26LN457U (CHASSIS:LC31A / LD31T) service manuals if exist.