Read LG 32LC7D (CHASSIS:LA73E) Service Manual online
- 37 -
- TV/CATV doesn't display
Check TU4001 Pin9(Video
output)
Can y
o
u see t
h
e n
o
rmal sign
al?
Check the input(Pin63) of
A
V
s
w
itch(IC5003).
Can y
o
u see t
h
e n
o
rmal
w
a
v
e
form?
Check the output(Pin56) of
A
V
s
w
itch(IC5003).
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
Check the input(Pin1) of
LP
F(IC4006).
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
YE
S
YE
S
YE
S
NO
Could y
ou measure
v
o
ltage of TU4001 &
IIC lines?
A
re they
all normal?
Check the output(Pin8)
of LPF(IC4006).
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
YE
S
Check the input(PinH26) of
BCM35
50(IC4
006).
Measu
re w
a
v
e
form at C101
0
b
ecau
se it
s
more easy
to
check.
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
YE
S
NO
You should check po
w
e
r
line
& IIC li
nes.
YE
S
You should replace TUNER.
NO
A
ft
e
r checking the Po
w
e
r
of
A
V
s
w
itch y
ou
should decide
to replace
A
V
s
w
itch or
not.
NO
A
ft
e
r checking the Po
w
e
r
of
A
V
s
w
itch y
ou
should decide
to replace
A
V
s
w
itch or
not.
NO
A
fte
r checking the
Po
w
e
r
o
f LPF y
ou sho
u
ld
decide to replace LPF or not.
NO
A
fte
r checking the
Po
w
e
r
o
f LPF y
ou sho
u
ld
decide to replace LPF or not.
YE
X
This board ha
s big
problem
because Main
chip(BCM3
550)
hav
e some trouble
s.
A
fter checking thorough
ly
all path
once
again,
You should decide to replace BCM3550 o
r not.
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