LG 47LG30D (CHASSIS:LB81A) Service Manual ▷ View online
C
2008
- 17 -
5. RGB PC doesn’t display
Check J703 ,
Can you see the normal waveform?
Check the input of RGB Audio
switch(IC1001) ,
Can you see the normal waveform?
Check the output of RGB Audio
switch(IC1001) ,
Can you see the normal waveform?
YES
YES
YES
NO
J703
may have problem. Replace this Jack.
NO
After checking the Power of RGB Audio switch,
you should decide to replace RGB Audio switch
or not.
NO
After checking the Power of RGB Audio switch
you should decide to replace RGB Audio switch
or not.
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main IC(IC100) you
should decide to replace Main IC or not.
This board has big problem because Main
IC(IC100) have some troubles.
After checking thoroughly all path once again,
You should decide to replace Main Board or not.
Check the input of RGB Video
switch(IC700) ,
Can you see the normal waveform?
NO
After checking the Power of RGB Video switch,
you should decide to replace RGB Video switch
or not.
YES
- 18 -
C
2008
6. HDMI doesn’t display
Check input connect J900 , J901, J902
Can you see the normal waveform?
Check DDC communication lines(IC900,
IC901, IC903 Pin5,6)
Check the input of HDMI Seitch(IC902)
This signal is TMDS.
Can you see the normal waveform?
YES
YES
NO
J900 , J901, J902
may have problem. Replace this Jack.
Check the output of HDMI Switch(IC902).
Can you see the normal waveform?
YES
YES
NO
After checking the trace of TMDS lines and power of
HDMI Switch, you should decide to replace HDMI
Switch or not.
NO
NO
After checking the Power of this chip, you
should decide to replace this or not.
After checking the Power of HDMI Switch you
should decide to replace MST3361 or not.
YES
Check HDCP communication lines(IC902)
NO
After checking the Power of this chip, you
should decide to replace this or not.
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main IC(IC100) you
should decide to replace Main IC or not.
This board has big problem because Main
IC(IC100) have some troubles.
After checking thoroughly all path once again,
You should decide to replace Main Board or not.
C
2008
- 19 -
BLOCK DIAGRAM
(Taiwan_Mstar)
LGE7363C
(IC100)
NT
P3000A
(IC802)
SP
(R+/-)
SP
(L+/-)
P801
5
V
_ANT
_MNT
EEP
RO
M
K
IA7427 (IC
101
)
24
C512
(I
C
103
)
I2
C
_
A
_
T
U
KE
Y
1
/2
TV Tuner
B
OOSTER
SIF
TV
_CV
BS
DDR Memor
y*
2
256Mb (IC200/
201)
DSUB
_R/
G/B
P
C
_L/
R_
IN
C
O
M
P
1/2_Y
/Pb/P
r
C
O
M
P
1/2_L
/R
_I
N
DSUB
_H/
V
_S
Y
N
C
M
A
X323
(I
C
601
)
DDC/U
A
RT-T
x
/Rx
PS421
(IC705)
HDMI_
I2
C
HDMI_
I2C_
0
HDMI_CEC
HDMI_Rx
TMDS
HPD
HPD
HDMI_CEC
USB
_DM/DP
5
V
_HDMI
TU_T
S
_DA
TA
P1001
L
E
D_
G/R &
IR
Flash Memor
y
8MB (IC107)
AV
_RO
UT
AV
_CVB
S
_
O
U
T
LCD Panel
FHD/HD
RES
ET
I2
C
I/O Expander
(IC106)
I2
C
_D_
T
U
TS_Serial
Flash Memor
y
8MB (IC105)
I/O Expander
(IC108)FRC O
nl
y
MS_
LRCH/
LRC
K/
SCK
AMP
_RST
S
T
M
A
V340
(I
C
500
)
Y/
P
b
/P
r
2
2
MC74HC
(I
C
801
)
C
om
p_L/
R
A
V
_LO
U
T
HDCP E
EPR
OM
(I
C
109
)
YAMAHA
(IC803)
S
PK_
N
S
PK_
P
FHD: P301
HD: P302
TV Tuner
5
V
_ANT
_MNT
B
OOSTER
SIF
TV
_CV
BS
I2
C_
D_
T
U
TS
_S
erial
Rear
Rear
3
3
Si
de
Si
de
1
1
FRC B/D
C
2008
- 20 -
MEMO
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