LG 42LG60FD (CHASSIS:LB81B) Service Manual ▷ View online
- 17 -
5. RGB PC doesn’t display
Check P501 ,
Can you see the normal waveform?
YES
NO
P501
may have problem. Replace this Jack.
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main IC(IC100) you
should decide to replace Main IC or not.
This board has big problem because Main IC(IC100)
have some troubles.
After checking thoroughly all path once again, You
should decide to replace Main Board or not.
6. HDMI doesn’t display
Check input connect JK701, JK702, JK703
Can you see the normal waveform?
Check DDC communication (IC705 Pin 1, 2, 24,
25, 51, 52, 74, 75)
Check the input of HDMI Seitch(IC705)
This signal is TMDS.
Can you see the normal waveform?
YES
YES
NO
JK701, JK702, JK703
may have problem. Replace this Jack.
Check the output of HDMI Seitch(IC705).
Can you see the normal waveform?
YES
YES
NO
After checking the trace of TMDS lines and power of HDMI
Switch, you should decide to replace HDMI Switch or not.
NO
NO
After checking the Power of this chip, you should
decide to replace this or not.
After checking the Power of HDMI Switch you should
decide to replace this or not.
YES
Check HDCP communication lines(IC109)
NO
After checking the Power of this chip, you should
decide to replace this or not.
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main IC(IC100) you
should decide to replace Main IC or not.
This board has big problem because Main IC(IC100)
have some troubles.
After checking thoroughly all path once again, You
should decide to replace Main Board or not.
- 18 -
BLOCK DIAGRAM
L
G
E
7
363C
(I
C
1
0
0
)
N
T
P
3000A
(I
C
8
02)
SP
(
R
+
/-
)
SP
(
L
+
/
)
)
-
P8
0
1
5
V
_A
N
T
_M
N
T
EEP
R
O
M
K
IA
7427
(I
C
1
01)
24C
5
1
2
(I
C
1
0
3
)
I2
C_
D_
T
U
/
I
2
C
_
A
_
T
U
KEY1
/
2
TV Tuner
B
OOS
T
E
R
SI
F
TV
_
C
V
B
S
DD
R
M
e
m
o
ry
*
2
256M
b
(
IC
200
/
2
01)
DS
U
B
_
R
/
G
/
B
P
C
_L
/
R
_I
N
COM
P
1
/
2
_
Y
/
P
b
/
P
r
COM
P
1
/
2
_
L
/
R
_
IN
D
S
U
B
_H
/
V
_S
Y
N
C
MAX
3
2
3
(I
C
6
0
1
)
D
DC/
U
A
R
T-T
x
/
R
x
PS
4
2
1
(I
C
7
0
5
)
HD
M
I_
I2C
HD
M
I
I2
C
_0
HD
M
I_
C
E
C
HD
M
I_
R
x
TM
D
S
HP
D
HP
D
HD
M
I
_
C
E
C
US
B
_
D
M
/
D
P
5V
_
H
D
M
I
TU
_
T
S_
D
A
TA
P
100
1
LE
D
_
G
/
R
&
I
R
Fl
a
s
h
Me
m
o
ry
8M
B
(
IC
1
07)
AV
_
R
O
U
T
AV
_
C
V
B
S
_
O
U
T
LC
D
P
a
n
e
l
FH
D
/
H
D
RE
S
E
T
I2
C
I/
O
E
x
p
a
n
d
e
r
(I
C
106)
I2
C_
D_
T
U
TS_Serial
Fl
a
s
h
Me
m
o
ry
8M
B
(
IC
1
05)
4
I/
O
E
x
p
a
n
d
e
r
(I
C
1
0
8
)F
R
C
O
n
ly
MS
_
L
R
C
H
/
LR
C
K
/
S
C
K
AM
P
_
R
S
T
ST
M
A
V
3
4
0
(I
C
5
00)
Y/
P
b
/
P
r
2
MC
7
4
H
C
(I
C
8
01)
Co
m
p
_
L/R
AV
_
L
O
U
T
H
D
C
P
EEP
R
O
M
(I
C
109)
YA
M
A
H
A
(I
C
8
0
3
)
SPK_
N
SPK_
P
F
H
D
: P
301
HD
: P
3
0
2
- 19 -
MEMO
- 20 -
300
200
801
400
900
540
820
840
530
550
580
810
120
500
121
560
510
803
804
520
830
805
802
200T
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.
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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