LG 42LB7DF (CHASSIS:LJ81A) Service Manual ▷ View online
- 37 -
Make sure you can
’t hear any audio
Check Signal
L504, L505
Replace it.
Check Signal
L508, L509, L510, L511
Y
N
Check IC501 Power 19V, 3.3V, 1.8V
L500, L501, L502, L503
Replace L
Y
N
Y
Replace it
N
Check Connector
P500
Y
Check BCM3553 I2S Output
R627, R628, R629
Y
Replace it.
N
Replace connector
N
Check speaker
Y
Replace speaker
N
Maybe NTP3000 has problems. Replace it
Y
TROUBLESHOOTING
9. All Source Video
9-2. Troubleshooting
- 38 -
Flash
(32MB)
DDR1(128MB)
(16Mx16x4)
DDR1(128MB)
(16Mx16x4)
TEA6420
Audio
SW
MTV416
(M
icom
)
NTP3000
(Digital AMP)
64Bit I/F
RGB-PC
HDMI
1/2/3
COMP 1
COMP 2
AV1
AV2
RGB-PC
I2S
MCLK
Digital out
COMP1
COMP2
AV1
AV2
BCM7412
(MPEG4
Decoder)
Analog
/Digital
Tuner
TC90512
DVI
I2S
SIF
SPDIF Out
CVBS
CVBS/Y/C
Y/
Cb
/Cr
R/G/B
DDR1
(64MB)
CS5340
L/R
Serial TP
20bits
12bit YC 4:2:2
NIM TUNER
TMDS_RX+-
EPM240F
MNT out (Audio Only)
TMDS341A
(3x1,S/W)
CVBS/Y/C
MC33078
(AMP)
L/R
RS232
RX/TX
DVI
4:2:2 20bit YC
Full HD(1080P)
WXGA(768P)
RF
Switch
DM1/DP1
Serial
TP
74HC04
SPDIF Out
(Coaxial)
Video
Front
End
Dual
HDMI
Rx
HD/SD
Video
Encoder
Audio
DSP
USB2.0
PKT
HSX
PCI/
EBI
HD-DVI
IB0
Parse2
RSBUF
XCBUF
RMX0
BCM3553
Local KEY
24C16
74LVC14APW
X-tal(54M)
Reset
KIA7029
NVRAM
I2C
TROUBLESHOOTING
10. Digital TVAudio
10-1. Block Diagram of Troubleshooting
- 39 -
Check video output
Follow procedure All source audio trouble
shooting
Y
Follow procedure digital TV video
trouble shooting
N
N
Maybe BCM3553 internal audio DSP has
problems. Replace it
TROUBLESHOOTING
10. Digital TVAudio
10-2. Troubleshooting
- 40 -
Flash
(32MB)
DDR1(128MB)
(16Mx16x4)
DDR1(128MB)
(16Mx16x4)
TEA6420
Audio
SW
MTV416
(
Micom
)
NTP3000
(Digital AMP)
64Bit I/F
RGB-PC
HDMI
1/2/3
COMP 1
COMP 2
AV1
AV2
RGB-PC
I2S
MCLK
Digital out
COMP1
COMP2
AV1
AV2
BCM7412
(MPEG4
Decoder)
Analog
/Digital
Tuner
TC90512
DVI
I2S
SIF
SPDIF Out
CVBS
CVBS/Y/C
Y/
Cb
/Cr
R/G/B
DDR1
(64MB)
CS5340
L/R
Serial TP
20bits
12bit YC 4:2:2
NIM TUNER
TMDS_RX+-
EPM240F
MNT out (Audio Only)
TMDS341A
(3x1,S/W)
CVBS/Y/C
MC33078
(AMP)
L/R
RS232
RX/TX
DVI
4:2:2 20bit YC
Full HD(1080P)
WXGA(768P)
RF
Switch
DM1/DP1
Serial
TP
74HC04
SPDIF Out
(Coaxial)
Video
Front
End
Dual
HDMI
Rx
HD/SD
Video
Encoder
Audio
DSP
USB2.0
PKT
HSX
PCI/
EBI
HD-DVI
IB0
Parse2
RSBUF
XCBUF
RMX0
BCM3553
Local KEY
24C16
74LVC14APW
X-tal(54M)
Reset
KIA7029
NVRAM
I2C
TROUBLESHOOTING
11. Analog TVAudio
11-1. Block Diagram of Troubleshooting
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