LG 42LGX (CHASSIS:LA84B) Service Manual ▷ View online
- 25 -
C
2008
Check TU1 Pin14(SIF)
Can y
ou see t
h
e n
o
rmal sign
al?
Check the input (Pin
A
N
23) of BCM3553((I
C100).
Measure
w
a
v
e
form at C665
because it
ís more easy
to
check.
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
YES
NO
Could y
o
u measu
re
v
o
ltag
e o
f T
U
1 & IIC lin
es?
A
re they
all normal?
NO
You should check po
w
e
r
line
& IIC li
nes.
YES
You should replace TUNER.
NO
A
ft
e
r checking audio signal line, y
ou sh
ould decide
to
replace item or not.
TV/CATV
- 26 -
C
2008
Check JK
701,
JK70
7, JK70
0, JK702, JK
703
.
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
NO
JK701, JK707, JK700, JK702, JK703 may
h
a
v
e
problem. Replace this
Jack.
Check the input (Pin
A
IN
6
A
,
A
IN6
B
,A
IN1
A
,A
IN1
B,
A
IN3
A
,A
IN3
B,
A
IN
4
A
,A
IN4
B
,A
IN2
A
,A
IN2
B
) of CS5345(IC
500).
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
NO
YES
A
ft
e
r checking audio signal line, y
ou sh
ould decide
to
replace item or not.
YES
Check the Output (Pin SDOU
T,SCLK,LRCK) of CS5345(I
C500).
Can y
o
u see t
h
e n
o
rmal
w
a
v
e
form?
NO
A
ft
e
r checking the Po
w
e
r &
MLCK & reset of this chip,
y
ou should
decide to replace this or not.
YES
Check the input (Pin
A
H
24,A
J24,
A
K
24) of
BCM3553((IC100).
Measure
w
a
v
e
form at R554,
R561,R
555 b
e
cause it
ís mo
re
eas
y
to
ch
e
ck.
Can y
o
u see t
h
e n
o
rmal
w
a
v
e
form?
NO
A
ft
e
r checking audio signal line, y
ou sh
ould decide
to
replace item or not.
AV/Component/RGB-PC
- 27 -
C
2008
Check input c
onnect JK600,
JK601,JK602,JK708
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
Check DDC commu
nication lines
(IC601, IC602,I
C603, IC701)
JK60
0,JK6
01,
JK70
8 ma
y
h
a
v
e
p
roblem. R
e
place th
is Jack.
Check the output of
PI3HDMI341
A
T
R(IC600)_HDMI1/2/3
or TMDS141H
A
R
(I
C703)_H
D
M
I4.
Can y
o
u see t
h
e n
o
rmal
w
a
v
e
form?
A
ft
e
r checking the Po
w
e
r
of this chip, y
o
u should
decide to
replace this or not.
Check HD
CP co
mmunicatio
n lin
es(IC102)
A
ft
e
r checking the Po
w
e
r
of this chip, y
ou should
decide to replace this or not.
YES
YES
YES
NO
NO
NO
NO
A
ft
e
r checking the Po
w
e
r &
Select Pin
&
Etc of this
chip, y
o
u should
decide
to replace this or not.
HDMI
- 28 -
C
2008
Check th
e o
u
tput (Pin
A
K
25
,A
L25,
A
J
25) o
f BCM355
3(IC
100).
Measure
w
a
v
e
form at R2635
,R2636,R
263
7 because it
ís more easy
to
check.
Can y
ou see t
h
e n
o
rmal sign
al?
Check the input (Pin 17,18,19) of NTP3000((IC501).
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
YES
NO
NO
This board ha
s big
problem
because Main chip(BCM3553) ha
v
e
some troubles.
A
ft
e
r ch
ec
kin
g th
orou
ghly
all p
a
th
once ag
ain
, You
sho
uld d
ecid
e
to rep
lace BCM
3553 o
r n
o
A
ft
e
r checking audio signal line, y
o
u sh
ould decide
to
replace item or not.
YES
Check the output (Pin 30,31,36,37,47,
48,53,54) of NTP3000((IC501).
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
NO
YES
A
ft
e
r checking the Po
w
e
r &
I2C & Reset of this ch
ip, y
o
u should
decide
to replace this or n
o
Check the spe
aker output
w
a
fer P501.
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
NO
YES
A
ft
e
r checking audio signal line, y
o
u sh
ould decide
to
replace item or not.
Check the connector & Speaker
* If
condition of starting
sound i
s
abnomal
,
y
ou hav
e
to
chec
k
IC1000(TP
A3005).
Speaker
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