LG 52LG72-UA (CHASSIS:LA86B) Service Manual ▷ View online
- 33 -
C
2008
S
peaker
Audio(Out)
Check th
e o
u
tput (Pin
A
K
25
,A
L25,
A
J
25) o
f BCM355
x(IC
100).
Measure
w
a
v
e
form at R263
5
,R2636,R
263
7 b
ecause itís mo
re eas
y
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
NO
NO
This board ha
s big
problem
because Main chip(BCM355x) ha
v
e
some troubles.
A
ft
e
r ch
ec
kin
g th
orou
ghly
all p
a
th
once again
, You
sho
uld d
ecid
e
to rep
lace BCM
355x o
r n
o
t.
A
ft
e
r checking audio signal line, y
o
u should
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?
YES
A
ft
e
r checking the Po
w
e
r &
I2C & Reset of this chip, y
o
u should
decide to replace this or not.
Check the spe
aker output
w
a
fer P501.
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
YES
A
ft
e
r checking audio signal line, y
o
u should
decide to
replace item or not.
Check the connector & Speaker
- 34 -
C
2008
S
pdif & Coaxial
Audio(Out)
Check th
e o
u
tput (Pin
A
P
11
) o
f BCM355x(
IC100).
Measu
re w
a
v
e
form at R263
8
b
ecau
se itís mo
re eas
y
to
check.
Can
y
o
u see t
h
e n
o
rmal sign
al?
Check th
e in
pu
t o
f JK500, JK501.
Can y
o
u see t
h
e n
o
rmal
w
a
v
e
form?
YES
NO
NO
This board ha
s big
problem
because Main chip(BCM355x) ha
v
e
some troubles.
A
ft
e
r ch
ec
kin
g th
orou
ghly
all p
a
th
once again
, You
sho
uld d
ecid
e
to rep
lace BCM
355x o
r n
o
t.
A
ft
e
r checking audio signal line, y
o
u should
decide to
replace item or not.
YES
A
ft
e
r checking the Jack, y
o
u should
decide to replace item or not.
- 35 -
C
2008
M
nt out
Audio(Out)
Check the output (Pin
A
N
28,
A
P
29) of BC
M355x(IC100).
Measure
w
a
v
e
form at R685, R686 because itís more easy
to check.
Can y
ou see t
h
e n
o
rmal sign
al?
NO
This board ha
s big
problem
because Main chip(BCM355x) ha
v
e
some troubles.
A
ft
e
r ch
ec
kin
g th
orou
ghly
all p
a
th
once again
, You
sho
uld d
ecid
e
to rep
lace BCM
355x o
r n
o
t.
Check th
e in
pu
t o
f JK704.
Can
y
ou see t
h
e n
o
rmal
w
a
v
e
fo
rm?
YES
NO
A
ft
e
r checking audio signal line, y
ou should
decide to
replace item or not.
YES
A
ft
e
r checking the Jack, y
o
u should
decide to replace item or not.
- 36 -
C
2008
EXPLODED VIEW
510
121
121
120
122
300
500
200
803
800
804
805
806
801
802
530
900
550
840
820
540
830
520
521
400
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.
IMPORTANT SAFETY NOTICE
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