LG 37LC7D Series, Service Manual

Page: 39 / 60

- 39 -
- Video doesn't display
Check J5007 Pin3C
Can y
o
u see t
h
e n
o
rmal
w
a
v
e
form?
Check the input(Pin1 or Pin8) of
A
V
s
w
itch(IC5003
). Pin
1
is fo
r
v
ideo1,Pin8
is
for v
ideo
2.
Can y
ou 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
J5007 may
hav
e
problem. Replace this
Jack.
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 its
more easy
to
check.
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
YE
S
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.