LG 26LT673H (CHASSIS:LA2AM) Service Manual ▷ View online
- 17 -
HDMI Video Trouble Shooting guide
Check JK800/JK801/JK802
Can you see the normal waveform?
N
JK800/JK801/JK802 may have problem. Replace this Jack.
This board has big problem because Main chip (Mstar) have some troubles.
After checking thoroughly all path once again, You should decide to replace Mstar or not.
Y
Check input signal format.
Is it supported?
Y
Check AC cable for damage
For damage or open conductor
Y
Y
Check HDCP key NVRAM(IC103)
Power & I2C signal
N
Replace the defective IC
RGB-PC Video Trouble Shooting guide
Check P900
Can you see the normal waveform?
NO
P900 may have problem. Replace this Jack.
Check the input of Mstar(IC101).
Measure waveform at R4042, R4025
because it’s more easy to check.
Can you see the normal waveform?
YES
This board has big problem because Main chip (Mstar)
have some troubles.
After checking thoroughly all path once again, You
should decide to replace Mstar or not.
YES
Check input signal format.
Is it supported?
YES
Check AC cable for damage
For damage or open conductor
YES
- 18 -
Analog RF Audio Trouble Shooting guide
Check RF Cable & Signal
Check Audio AMP output
L503,L504,L505,L506
Y
Check TU3001 Pin1 (SIF Output)
Can you see the normal signal?
Y
Could you measure voltage of TU3001& IIC lines?
Are they all normal?
N
You should check power line &
IIC lines.
N
You should replace TUNER.
Y
Check IC501
Y
Replace IC501
N
Replace L503,L504,L505,L506
N
Check the input of Mstar (IC101).
Measure waveform at C250, C251 because it’s more
easy to check.
Can you see the normal waveform?
Y
After checking audio signal line, you should decide to replace
item or not.
N
AV/Component/RGB-PC Audio(in)Trouble shooting guide
Check input signal format.
Is it supported?
Check JK1700, P900
Can you see the normal
waveform?
Replace JK1700, P900
Y
N
Check AC cable for damage
For damage or open conductor
Y
Y
Check the input of Mstar(IC101).
Measure waveform at C236, C237, C244, C245 because it’s more easy to
check.
Can you see the normal waveform?
Y
Check Audio AMP output
L503,L504,L505,L506
Y
Replace L503,L504,L505,L506
N
This board has big problem because Main chip (Mstar) have some troubles.
After checking thoroughly all path once again, You should decide to replace Mstar or not.
- 19 -
HDMI Audio in Trouble Shooting guide
Check input signal format.
Is it supported?
Check JK800/JK801/JK802
Can you see the normal
waveform?
Replace JK800/JK801/JK802
Y
N
Check AC cable for damage
For damage or open conductor
Y
Y
Check Audio AMP output
L503,L504,L505,L506
Y
Replace L503,L504,L505,L506
N
This board has big problem because Main chip (Mstar) have some troubles.
After checking thoroughly all path once again, You should decide to replace Mstar or not.
Audio out Trouble shooting guide
Check the output of Mstar(IC101).
Measure waveform at R148, R503, R504.
because it’s more easy to check. Can you see the normal signal?
YES
NO
This board has big problem because Main chip
(MStar) have some troubles.
After checking thoroughly all path once again,
You should decide to replace Mstar or not.
Check Audio AMP output L503,L504,L505,L506
Can you see the normal waveform?
NO
YES
After checking the Power & I2C & Reset of this chip,
you should decide to replace this or not.
Check the speaker output wafer P501.
Can you see the normal waveform?
NO
YES
After checking audio signal line, you should decide
to replace item or not.
Check the connector & Speaker
- 20 -
BLOCK DIAGRAM
K4
B2
G
16
46
E
-BC
K0
2G
BI
T
80
0MH
z
(1
60
0)
IC
12
01
N
AN
D
F
la
sh
H
Y2
7U
F0
82
G
2B
TPC
B
2G
BI
T
IC
10
2
D
ig
ita
l AMP
N
TP7
50
0L
IC
16
00
I2S
A_
D
at
a[
0:
15]
,
K4
B1
G
16
46
G
-BC
K0
1G
BI
T
80
0MH
z
(1
60
0)
IC
12
02
B_
D
at
a[
0:
15]
,
Ad
dr.
[ ]
, c
trl,
D
QS,
D
M
…
PC
M
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7]
IF
N
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TU
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(SVC
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et
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20
0
Po
w
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AMP
TPA3
12
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2PW
PR
IC
18
00
JK18
01
JK18
00
R
JP_C
TR
L
JK50
00
Pro
:Id
om
LG
D
T1
00
1
IC
12
09
TS_C
LK,
VALI
D
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C
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~7
PM
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C
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TMMB -H
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B
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AN
TV
-link
C
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Ga
m
e
co
nt
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Au
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A
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JK70
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JK17
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D
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H
D
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R
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PC
AV
U
SB
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/V
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VBS,
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M
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JA
C
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PA
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H
D
MI
3
SPD
IF
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