LG 52LG70-UA (CHASSIS:LA86A) Service Manual ▷ View online
- 25 -
C
2008
T
V/CATV
Check T
U
1 Pin14(SIF)
Can you see the normal signa
l?
Check the input (Pin AN23) of BCM3553((IC
100).
Measure
w
a
vef
orm at C665 b
e
cause its mor
e eas
y
to ch
ec
k.
Can
you se
e the normal
w
a
vef
orm?
YES
NO
Coul
d
you mea
sure voltag
e of T
U
1 & IIC lines?
Are they
a
ll nor
mal?
NO
You should check po
w
e
r l
ine
& IIC lines.
YES
You shou
ld rep
lace T
UNER.
NO
After checking audio signal line,
y
ou sh
ould decide to replac
e
item or not.
Audio(In)
- 26 -
C
2008
A
V/Component/RGB-PC
Audio(In)
Check JK701, JK707, JK700,
JK702, JK703.
Can
you se
e the normal
w
a
vef
orm?
NO
JK701, JK707, JK700, JK702, JK703 may ha
ve problem. Replace this
Jack
.
Check the in
put (Pin AIN6A,
AIN6B,AIN1A,AIN1B,
AIN3A,AIN3B,AIN4A,AIN4B,AIN2A,AIN2B) of CS5345(IC
500).
Can
you se
e the normal
w
a
vef
orm?
NO
YES
After checking audio signal line,
y
ou sh
ould decide to replac
e
item or not.
YES
Check the Output (Pin SDOU
T,SCLK,LRCK)
of CS5345(IC
500).
Can
you se
e the normal
w
a
vef
orm?
NO
After checking
the Po
w
e
r & MLCK & reset of this chip,
yo
u shou
ld dec
ide to repl
ace this or not.
YES
Check the in
put (Pin AH24,AJ24,AK24) of BCM355
3((IC100).
Measure
w
a
vef
orm at R554,R
561,R555 bec
ause its more e
as
y
to check.
Can
you se
e the normal
w
a
vef
orm?
NO
After checking audio signal line,
y
ou sh
ould decide to replac
e
item or not.
- 27 -
C
2008
HDMI
Audio(In)
Check input connect JK600,J
K601,JK602,JK708
Can
you se
e the normal
w
a
vef
orm?
Check DDC communication lines
(IC601, IC602,I
C603, IC701)
JK600,JK601,JK708 may hav
e problem. Replace this Jack.
Check the outp
ut of PI3HDMI341AT
R(IC600
)_HDMI1/2/3
or T
M
DS141HAR(IC703)_HDMI4.
Can
you se
e the normal
w
a
vef
orm?
After checking
the Po
w
e
r of this chip,
y
ou should decide to replac
e this or not.
Check HDCP communication lines(IC102)
After checking
the Po
w
e
r of this chip,
y
ou should decide to replac
e this or not.
YES
YES
YES
NO
NO
NO
NO
After checking
the Po
w
e
r & Select Pin & Etc of this chip,
yo
u shou
ld dec
ide to repl
ace this or not.
- 28 -
C
2008
S
peaker
Audio(Out)
Check the outp
ut (Pin AK25,AL25,AJ25) of B
C
M3553(IC100).
Measure
w
a
vef
orm at R2635,
R2636,R2637
because its more eas
y to check.
Can you see the normal signa
l?
Check the input (Pin 17,18,19) of N
T
P3000((
IC501).
Can
you se
e the normal
w
a
vef
orm?
YES
NO
NO
T
h
is board has big problem because Main c
h
ip(BCM3553) have some troubles.
After checking
thoroug
hl
y al
l p
a
th once ag
ain
,
You should decide to replace
BCM3553 or not.
After checking audio signal line,
y
ou sh
ould decide to replac
e
item or not.
YES
Check the output (Pin 30,31,3
6,37,47,48,53,54) of NT
P3000((IC501).
Can
you se
e the normal
w
a
vef
orm?
NO
YES
After checking
the Po
w
e
r & I2C & Reset of this chip,
yo
u shou
ld dec
ide to repl
ace this or not.
Check the speaker output
w
a
fer P501.
Can
you se
e the normal
w
a
vef
orm?
NO
YES
After checking audio signal line,
y
ou sh
ould decide to replac
e
item or not.
Check the connector & Speaker
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