LG 42LGX (CHASSIS:LA84B) Service Manual ▷ View online
- 29 -
C
2008
Check th
e o
u
tput (Pin
A
P
11
) o
f BCM3553(
IC100).
Measu
re w
a
v
e
fo
rm at R263
8
b
ecau
se it
ís more easy
to
check.
Can y
ou see t
h
e n
o
rmal sign
al?
Check th
e in
pu
t o
f JK500, JK501.
Can y
ou see t
h
e n
o
rmal
w
a
v
e
form?
YES
NO
NO
This board ha
s big
problem
because Main chip(BCM3553) ha
v
e
some troubles.
A
ft
e
r ch
ec
kin
g th
orou
ghly
all p
a
th
once ag
ain
, You
sho
uld d
ecid
e
to rep
lace BCM
3553 o
r n
o
t.
A
ft
e
r checking audio signal line, y
o
u sh
ould decide
to
replace item or not.
YES
A
ft
e
r checking the Jack, y
o
u should
decide to replace item or not.
Spdif&Coaxial
- 30 -
C
2008
Check the output (Pin AN
28,
AP29) of BCM3553(IC100).
Measure
wavef
orm at R685, R
686 beca
use itís
more eas
y
to
check.
Can y
o
u see the normal signal?
NO
This board has big problem because Ma
in
chip(BCM3553) have some t
r
oubles.
After checking
thoroughly
all path once again
, You should
decide
to
repla
ce
BCM3553 or n
o
t.
Check the input of JK704.
Can y
o
u se
e the nor
mal
w
ave
for
m?
YES
NO
After ch
ecking
audio s
ignal lin
e,
you
s
h
ou
ld d
ecide to
r
e
place
item
or n
o
t.
YES
After ch
eck
ing
th
e Jack
,
you
s
h
ou
ld d
ecid
e to
rep
lace
item
or
not.
MNT OUT
C
2008
- 31 -
BLOCK DIAGRAM
F
lash
(1
6MB)
DDR(
3
2
MB)
(4x16x
4
)
DDR(
3
2
MB)
(4x16x
4
)
74LVC14APW
C
S
5345
(Audio S/W
&A/D&)
MTV416
(Micom)
NTP
3
0
0
0
(D-AMP)
X200
X-tal(54
)
PI
3HDMI
3
4
1
ATR
(3x1,S/W
)
EEPROM
A
T
/NT Tune
r
64Bit I/F
R
eset
CVBS
CVBS/Y/C
Y/Cb/Cr
R/G/B
H/V Sy
nc
Audio L/R
I2S
MNT out
(L/R)
SPDIF
OUT
I2S
Dual LVDS
Connector(40P)
Full H
D
(1080
P)
RS-232
C
Dead IC
w
h
e
n
Standby
A
li
v
e IC
w
h
en
Standby
Video
Fro
nt
End
Du
al
HDMI
Rx0
HD/SD
Video
Encoder
Aud
io
DSP
BCM3552(HD)
BCM3553(FHD)
MCLK
MCLK
HDMI CEC
HDMI CEC(To
M
ico
m)
To Micom
SDA
SCL
SIF
IF(AT)
Buffer
Digital out
Buffer
Buffer
24
C16
AGC CTL (Fr
o
m BCM)
USB2.
0
I2S Audio Input
VSB/
QAM/NTSC/S
IF
AV
1
COMP
1
COMP
2
DDR(
3
2
MB)
(4x16x
4
)
DDR(
3
2
MB)
(4x16x
4
)
DDR(
3
2
MB)
(4x16x
4
)
DDR(
3
2
MB)
(4x16x
4
)
DDR(
3
2
MB)
(4x16x
4
)
DDR(
3
2
MB)
(4x16x
4
)
DDR (1
2
8
MB)
RGB
Y/Cb/Cr
HDMI1
HDMI2
HDMI3
AV
1
COMP
1
COMP
2
RGB
C
o
axia
l
OUT (L
G
5
0)
USB
LG60: FHD-1
20
Hz
X400
X-tal(24
)
NVRAM
24
C512
EE
PRO
M
EE
PRO
M
EE
PRO
M
FRC
-
9459M
DDR (
6
4MB)
DDR(
3
2
MB)
(4
x16x
4
)
DDR(
3
2
MB)
(4x16x
4
)
DDR(
3
2
MB)
(4
x16x
4
)
DDR(
3
2
MB)
(4x16x
4
)
Dual LVDS
Connector(26P)
X1000
X
-t
a
l(
20.25
)
HDMI4
T
M
D
S
141H
AR
(1x1,
Equali
zer)
EE
PRO
M
Du
al
HDMI
Rx1
HDMI CEC(To
M
ico
m)
TPA3005D2
PHPR
G
4
IR & Local
KEY
- 32 -
EXPLODED VIEW
300
200
801
400
901
900
540
530
810
120
500
121
560
510
803
804
570
840
520
521
830
805
802
200T
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.
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
Click on the first or last page to see other 42LGX (CHASSIS:LA84B) service manuals if exist.