LG 37LG50D (CHASSIS:LJ82A) Service Manual ▷ View online
- 21 -
No OSD Trouble Shooting
Check Q903 P in #1
Voltag e Level 12V
Check
Power con necto r
Replace Power b oard
Check P90 0 or P902
#17(RCLK-) , #18(RCLK+)
Maybe BCM3553 has
proble ms
Check L VDS Cable
Check PDP/LCD Module
Control b oard
Y
NY
Y
N
Check L 900
Voltag e Level 12V
Replace L 901
Y
N
Y
Replace Cab le
N
- 22 -
Digital TV Video Trouble Shooting
Ch
eck RF
Cab
le
Ch
eck T
U
80
0 T
P
Clo
ck, Data,
Sy
nc
PIN#10 (38.1M
Hz), PIN#13,
PIN#14
May
b
e
Tuner(TU800) has
proble
m
s
Ch
eck BCM
3553 Ou
tp
u
t
TP
Clock, Data, Sy
nc
R153, R1
55, R152
Ch
eck BCM
74
12 Clo
ck, Hs
yn
c,
Vsy
n
c
R108
8 (T
y
p
. 7
4
.25MHz), R10
87,
R108
6
Y
Y
N
Check Tuner 5V Po
w
e
r
IC804 #3 Pin
Rep
lace IC80
4
Y
N
Y
May
b
e BCM3
553(IC10
0) h
as
proble
m
s
N
May
b
e BCM7
412(IC10
00) h
a
s
proble
m
s
N
Ch
eck PL
D Clo
ck, Hs
y
n
c,
Vsy
n
c
R110
2 (T
y
p
. 7
4
.25MHz), R11
00,
R110
1
Y
Redo
w
n
load
PLD file or re
place
N
May
b
e BCM3
553(IC10
0) h
as
proble
m
s
Y
Ch
eck T
UNER PIN#9
(ERROR FL
A
G
)
Bad Tuner. Replace Tuner.
LOW
HIGH
Check BCM
7412 Input Clock
R107 (2
7MHz)
Rep
lace it
N
Y
- 23 -
Analog TV Video Trouble Shooting
Check RF Cable
Check CVBS sig nal
TU800 #17 Pin
Maybe Tuner(TU800) has
proble ms
Check CVBS sig nal
IC808 #8 Pin
Check CVBS sig nal
C658
Y
Y
N
Check Tuner 5V Po wer
IC804 #3 Pin
Replace it
Y
N
Y
Replace IC808 or ch eck L 800 5V
po wer
N
Replace it
N
Y
Maybe BCM3553(IC100) has
proble ms
- 24 -
Component Video Trouble Shooting
Check sig nal fo rmat
Is it sup ported?
Check sig nal
L700, L701. L702 / L704, L705,
L706
Replace it.
Check sig nal
C638, C639, C640 / C628, C629,
C630
Y
Y
N
Check JK 700 / JK702
Replace connector
Y
N
Y
Replace it
N
Maybe BCM3553(IC100) has
proble ms
Y
Check Component Cable
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