LG 19LS4D (CHASSIS:LD83A) Service Manual ▷ View online
- 17 -
6. HDMI doesn’t display
Check input connect J900 , J901, J902
Can you see the normal waveform?
Check DDC communication lines(IC900, IC901,
IC903 Pin5,6)
Check the input of HDMI Seitch(IC902)
This signal is TMDS.
Can you see the normal waveform?
YES
YES
NO
J900 , J901, J902
may have problem. Replace this Jack.
Check the output of HDMI Switch(IC902).
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 MST3361 or not.
YES
Check HDCP communication lines(IC902)
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
LV
D
S
SC
2
_
L
/
R
_
IN
Sa
tu
rn
3
+
L
G
E
7
363C
S
T
M
A
V
340
(I
C
700
)
NTP3
0
0
0
A
SP
(
R
)
SP
(
L
)
SP
(
R
)
SP
(
L
)
P1
0
0
0
5
V
_A
N
T
_M
N
T
CI
S
lo
t
(P
8
0
1
)
EEP
R
O
M
KI
A
7
4
2
7
24C
5
12
I2
C
_
D
_
T
U
/
I2
C
_
A
_
T
U
K
EY1
/
2
TV Tuner
TV Tuner
B
OOS
T
E
R
SI
F
TV
_
C
V
B
S
SC
1
_
R
/
G
/
B
D
S
U
B
_
R
/G
/B
R/
G
/
B
PC
_
L
/
R
_
IN
COM
P
_
Y
/
P
b
/
P
r
COM
P
_
L
/
R
_
IN
D
S
U
B
_H
/
V
_S
Y
N
C
M
A
X
3232C
D
R
(I
C
7
02)
DD
C/
U
A
R
T-T
x
/
R
x
E
EPR
O
M
HDM
I_
I2
C
HD
M
I_
C
E
C
/
R
x
/
H
P
D
TMD
S
HP
D
US
B
_
DM
/
D
P
5V
_
H
D
M
I
PCM_ADD
PCM_DATA
TS_Parallel
TU
_
T
S_
D
A
TA
K
IC
7
S
Z
32F
U
(I
C
8
0
0
)
PCM_CD_ON
CI_
C
D
_
1
/
2
II
S
MUT
E
LE
D
_
G/
R
&
IR
Fl
a
s
h
M
e
m
o
ry
4M
B
(
IC
106
)
SC
1
_
C
V
B
S
_
IN
SC
2
_
C
V
B
S
_
IN
SC
1
_
TV
_
V
O
U
T
DT
V
/
M
N
T
_
V
_
O
U
T
SC
1
_
L
/
R
_
IN
T
V
_L
/
R
_O
U
T
DT
V
/
M
N
T
_
L
/
R
_
OU
T
LC
D
P
a
n
e
l
RE
S
E
T
I2
C
TS_Serial
74L
V
C
541A
(I
C
8
01)
Fl
a
s
h
M
e
m
o
ry
4M
B
(
IC
102
)
DDR
M
e
m
o
ry
256M
b
(
IC
3
0
0
)
II
C
(E
y
eQ
II)
MEMO
- 19 -
- 20 -
300
200
531
530
580
520
521
523
400
120
590
591
910
900
920
150
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.
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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