LG 42LB9RTA (CHASSIS:LP7BB) Service Manual ▷ View online
- 21 -
15. In case of becomes un
usual d
isplay
from comp
onent1 mo
de(main/sub)
16. In case of becomes un
usual d
isplay
from component 2 mode(main/sub)
17. In case of becomes un
usua
l display
from RGB mode(main/sub)
Is normal video
input
of the JK102?
(Check L126, L127, L128)
Check the input source
Is normal video
input
of the JK103?
(Check L129, L130, L131)
Is normal R, G, B input
and H,V s
y
nc
of the JK500?
(Check R509, R511, R512
R513, R5
15)
Check the input source
Check the input source
Chan
ge IC(IC7
00)
Chan
ge IC(IC7
00)
Chan
ge IC(IC7
00)
YE
S
NO
YE
S
NO
YE
S
NO
- 22 -
Sy
mpto
m
L
E
D
is
Green
S
c
re
e
n
i
s
e
x
istent, but
so
und isn't
C
h
eck f
o
llow
18. N
o Sound
All input (mode)
is no soun
d
?
Is the speaker
on in men
u?
Is the speaker
cable n
o
rmal
?
IC400 op
erate
normally
?
Set on speaker
in menu
Check the
Speaker cable
Repl
ace
IC400
IC401 op
erate
normally
?
Repl
ace
IC401
IC402 op
erate
normally
?
Repl
ace
IC402
Replace VSC
B/D
On
ly
HD
MI i
s
no
Soun
d
?
Do
w
n
load the EDID data
Only
AV input is
no
Soun
d
?
Is the output
of IC300(pin52,53)
normal?
Check the signal
after IC300
refer to circuit diagr
am
Repl
ace
IC300
Only
RF is
no
Soun
d
?
Check the T
uner In/Out
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
- 23 -
No
Is
no
rm
a
l
on
ly
video
?
Is
no
rm
a
l
on
ly
aud
io?
C
heck
T
M
D
S
line
wa
ve.
(R
1215 ~ R1222/ R122
6 ~ R1233)
D
o
wn
load
EDID
da
ta each po
rt.
1
. Check
T
V
input mode.
(H
D
M
I1
por
t suppor
t
H
D
M
I and
D
V
I.
So
if you inpu
t D
V
I
s
igna
l
a
nd PC
a
u
d
io fr
o
m
phone jac
k
,
You can hear
PC
au
dio
.
)
2.
U
n
p
lug
a
n
d
plug
HDMI
c
a
b
le
.
(s
o
m
etimes
ESD
s
urge
occu
rr
ed
a
t
HD
MI
p
o
rt.)
3.
Ch
e
c
k
HDMI Mut
e
re
g
ister.
(0x
6
8,
o
ff
s
et
0x
3
7
)
4
. Check
A
udio
-
o
u
t chan
ne
l mu
te
reg
is
te
r
(0
x68
,
o
ffse
t
0
x
32)
is
approp
ri
a
te
ly enabled
.
C
h
eck
H
D
MI
sour
c
e
. Chan
ge anothe
r
so
ur
c
e
o
r cab
le
.
Is
wa
ve continuous?
1
. Check
H
D
MI r
e
c
e
ive
r'
s
s
ta
tus
reg
is
te
r.
(
0
x60,
o
ffset
0
x
06)
-
If t
h
e
v
a
lue
is
0xf
or
0x
8, it i
s
n
o
rm
al.
2
. Check
H
D
C
P
reg
iste
r.
(0
x60,
o
ffset
0x32
)
-
E
nabl
e
bit
6:
HDCP
key
loaded
-
E
n
a
b
le
bit
5:
HDCP
d
e
c
ry
p
tio
n
a
c
tiv
e
-
E
n
a
b
le
bit
4:
HDCP
a
ut
h
e
n
.
att
e
m
p
te
d
No
No
R
e
p
lace IC12
00
R
e
set
T
M
D
S
powe
r
down
/on
reg
iste
r
.
-
0
x
6
0
,
o
ffse
t
0x
3f
:
0xf
7
=>
0xff
Yes
Yes
N
o
rm
a
l video
,
No
rm
a
l
a
ud
io
?
Yes
No
19. HDMI mode
- 24 -
20.1 DVR
Start check
Is
T
imesh
ift
M
ode
"O
n
"
in
Menu?
Is
connected cab
le?
(P
1300, P130
2
)
Is
opera
ted
IC
1300,IC130
2
norm
ally?
C
hang
e T
imesh
ift
M
ode
from
off
t
o
"O
n"
C
onnect a cab
le
.
P1300, P130
2
R
e
p
lace the IC
1300, IC130
2
YE
S
YE
S
YE
S
NO
NO
NO
NO
Sy
mpto
m
L
E
D
is
Green
Doe
sn
't
w
o
rk
tim
e
shift
m
ode.
Can
't
enter to r
e
cord
e
d
li
s
t
Can
't r
e
c
o
rd
AV/RF/Com
ponent
C
h
eck f
o
llo
w
Is
opera
te
d
IC1500, IC150
1
norm
ally?
R
e
p
lace the IC
1500, IC150
1
C
hang
e H
D
D
YE
S
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