LG 42LG70YR (CHASSIS:LP81D) Service Manual ▷ View online
- 17 -
4. Unusual display from rear AV mode
.
5. Unusual display from Side AV mode.
6. Unusual display from Side S-Video mode.
7. Unusual display from component 1 mode.
8. Unusual display from component 2 mode.
9. Unusual display from RGB mode.
No
Yes
Is video input of the
A/V Jack normal?
(Check R8044)
Same as Block A
Same as Block A
Same as Block A
Check the input source.
Check the input source.
Check the input source.
Check the input source.
Change IC801
Change IC801
Change IC801
Is Video input of the
Comp1 jack normal?
(Check R8011,8012,8013)
Is Video input of the
Comp2 jack normal?
(Check R8030,8032,8033)
Is Video input of the
Comp2 jack normal?
(Check R8035,8037,8039)
Check the input source.
Check the input source.
Is video input of the
Side A/V Jack normal?
(Check R8043)
Is video input of the
S-Video Jack normal?
(Check R8041,8042)
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
- 18 -
10-1 Symptom
1) LED is green.
2) Screen display but sound is not output.
2) Screen display but sound is not output.
10. No Sound
10-2 Check process
All input(mode)
is no sound.
Only HDMI is
no sound
Only AV/
COM2/PC input is
no soudn.
Only RF is no sound.
Check the Tuner In/Out.
Check the signal after
IC600 refer to circuit
diagram
Is the output of
IC600 normal?
IC600 normal?
Download the EDID data.
No
No
No
No
No
Yes
Yes
Yes
Yes
Menu?
Normal
Normal
No
No
No
No
Yes
Yes
Yes
Yes
Replace
IC600
Is the speaker
on it men?
Set on speaker
in menu
Check the
Speaker cable
Replace
IC801
Replace
IC601
Is the speaker
cable normal?
cable normal?
IC801 operate
normal?
IC 601 operate
normal?
Replace Main B/D
- 19 -
BLOCK DIAGRAM
PC_Aud
io
RF
RGB
(PC On
ly)
HD
M
I1, 2
, 3
(DT
V
Only
)
AV1
MNT
_
O
U
T
Side AV2
COMP1
COMP2
USB
T
M
DS
/D
DC/
H
PD_SI
NK
H
D
MI
_
S
E
L
/H
D
MI
_
II
C
TM
D
S
Mu
x
T
M
DS/DD
C
/H
P
D
_
S
/W
T
X
CO
[0
:4
] /
T
X
CE
[0:4
] /
T
X
CLKO /
T
X
CLKE
RG
B/H
V
S/IIC_
D
SU
B
CV
BS
_V
IN
COM
P
1 Y
P
b
P
r
COM
P
2 Y
P
b
P
r
SI
D
E
_C
V
B
S/
SI
D
E
_Y
C
T
V
_
M
A
IN/
M
A
IN_
S
IF
AUD
IO
S/
W
COMPONENT
or
S
ID
E
IC602
SIF
A
M_A
U
D
IO
COM
P1_L
R
COM
P2_L
R
SI
D
E
_L
R
M
N
T
_LR_OUT
SW/LR
NTP3000
Digital AMP
SPK 2CH
/SPK_HOTEL
/SPK_HOTEL
24C02
EEPR
OM
DDC
HDM
I_5V_D
ET
(H
PD)
/H
PD
_
M
S
T
/CEC
24C02
EEPR
OM
PC
_
A
UD
CV
BS
_
L
R
IN
MN
T
_
V
O
U
T
(A
M
P
:
GA
IN
X 4)
/M
UT
E
_
L
IN
E
AM
P
GA
IN X
4
IC601
AUDIO_SW
DDC
SC
L/
S
D
A
_
T
U
N
E
R
SEC
A
M
_
L
DDR
(2
56MB
IT)
M
A
DR
[0:11]
MDA
T
A
[0
:1
5
]
SUB
DE
CODER
D
E
C_656[0
:7
]
/ D
E
C_656_CLK
SW_RESET / IIC_PART /
PIP_V(
GAIN
X 4)
SW
_
R
E
S
ET
/ IIC_P
A
R
T
I2S
MU
T
E
_
M
A
IN
/
A
C
_DE
T
A
M
P_M
U
T
E_HOT
EL
PSU
RL_ON/S
E
LECT
/
DI
M
M
ING/SY
NC
MN
T
_
5
V
/A
C_
DE
T
/S
C_R
S
T
AU
D
IO
_
R
Ms
ta
r
RA
M_
C
A
S
/RA
S
RA
M_
C
S
/W
E
R
A
M
_
CK
E/CLK
R
A
M
_
LDQS/UDQ
S
R
A
M
_
B
A
[0
:1
]
R
A
M
A
_[
0:
12
]
R
A
M
D
Q
S
_[
0:
1
5
]
FRC_R/G/B_Out_ 0 ~ 9
FRC_DEN/CLK_Out
FRC_HS/VS_Out
RA
M_
C
A
S
/RA
S
RA
M_
C
S
/W
E
R
A
M
_
CK
E/CLK
R
A
M
_
LDQS/UDQ
S
R
A
M
_
B
A
[0
:1
]
R
A
M
A
_[
0:
12
]
R
A
M
D
Q
S
_[
0:
1
5
]
SC
L/
S
D
A
_
P
A
R
T
FRC_RE
S
E
T
A
O
_
T
X
[0:
4]
A
E
_T
X[
0:
4
]
EO
_T
X[
0
:4
]
B
E
_
T
X
[0:
4]
A
O
/A
E
/EO
/B
E_CL
K
MODULE
SC
L/
S
D
A
_
P
A
R
T
SC
L/
S
D
A
_
P
A
R
T
HDMI_SCL/SDA
24C64
EEPROM
SCL/
SD
A_
PA
RT
SC
L/
S
D
A
_
P
A
R
T
IO
_
E
XP
A
NDE
R
SC
L/
S
D
A
_
P
A
R
T
DD
R2
(256
M
B
IT)
M
T
K (FRC
CHIP)
M
X
25L8005
FL
A
S
H MEMORY
(2
M
B
YTE
)
SP
I_CZ/CLK
SP
I_D
SP
I_CZ/CLK
SP
I_D
M
X
25L4005
FL
A
S
H MEMORY
(512
KBY
TE)
SP
I_CZ/CLK
SP
I_D
RESE
T
Zoran
V
A
DD
IS-
966X
D
MPEG
Decoder
DDR
M
E
M
US
B(
A
V
I
/O, D
a
ta
I/O
)
BD
20
41
Protect
IC
+5
V
SER
IA
L
FL
A
S
H
M
PEG
RX/T
X
M
PEG
RE
S
E
T
I2S IN
656 IN
To M
s
tar
- 20 -
EXPLODED VIEW
300
200
200T
200N
804
800
805
802
803
801
122
120
121
500
510
806
550
821
822
521
540
530
400
900
901
820
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.
IMPORTANT SAFETY NOTICE
Click on the first or last page to see other 42LG70YR (CHASSIS:LP81D) service manuals if exist.