LG 32LG70 (CHASSIS:LA86B) Service Manual ▷ View online
- 21 -
(4) HDMI - Audio(In)
Check DDC communication lines.
(IC601, IC602, IC701)
Yes
Check the output of PI3HDMI341ATR(IC600).
Can you see the normal waveform?
After checking the Power of this chip, you should
decide to replace this or not.
No
Check input connect JK600,JK601,JK708
Can you see the normal waveform?
Yes
JK600,JK601,JK708 may have problem. Replace
this Jack.
No
Check HDCP communication lines(IC102)
Yes
After checking the Power of this chip, you should
decide to replace this or not.
No
After checking the Power & Select Pin & Etc of
this chip, you should decide to replace this or not.
No
(5) Speaker - Audio(Out)
Check the input (Pin 17,18,19) of NTP3000 (IC501).
Can you see the normal waveform?
Yes
Check the speaker output wafer P501.
Can you see the normal waveform?
After checking audio signal line, you should decide to
replace item or not.
No
Check the output (Pin AK25,AL25,AJ25) of BCM355x (IC100).
Measure waveform at R2635,R2636,R2637 because it’s more
easy to check. Can you see the normal signal?
Yes
This board has big problem because Main chip (BCM355x)
have some troubles. After checking thoroughly all path once
again, You should decide to replace BCM355x or not..
No
Check the output (Pin 30,31,36,37,47,48,53,54) of NTP3000
(IC501). Can you see the normal waveform?
Yes
Check the connector & Speaker.
Yes
Check the output (Pin 30,31,36,37,47,48,53,54) of
NTP3000((IC501).Can you see the normal waveform?
No
After checking audio signal line, you should decide
to replace item or not.
No
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(6) Spdif & Coaxial - Audio(Out)
Check the input of JK500, JK501.
Can you see the normal waveform?
Yes
After checking audio signal line, you should
decide to replace item or not.
No
Check the output (Pin AP11) of BCM355x(IC100).
Measure waveform at R2638 because it’s more
easy to check. Can you see the normal signal?
Yes
This board has big problem because Main chip(BCM355x)
have some troubles. After checking thoroughly all path once
again, You should decide to replace BCM355x or not.
No
After checking the Jack, you should
decide to replace item or not.
(7) MNT out - Audio(Out)
Check the input of JK704.
Can you see the normal waveform?
Yes
After checking audio signal line, you should
decide to replace item or not.
No
Check the output (Pin AN28, AP29) of BCM355x (IC100).
Measure waveform at R685, R686 because it’s more
easy to check. Can you see the normal signal?
Yes
This board has big problem because Main chip(BCM355x)
have some troubles. After checking thoroughly all path once
again, You should decide to replace BCM355x or not.
No
After checking the Jack, you should
decide to replace item or not.
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BLOCK DIAGRAM
Audio L/R
Flash
(16MB)
74LVC14APW
TEA6420D
(Audio SW)
MC33078
(AMP)
CS5340
(A/D)
MTV416
(
M
icom
)
NTP3000
(D-AMP)
X200
X-tal(54
ß÷
)
PI3HDMI341ATR
(3x1,S/W)
EEPROM
AT/NT
Tuner
64Bit I/F
Reset
CVBS
CVBS/Y/C
Y/
Cb
/Cr
R/G/B
H/V Sync
Audio L/R
I2S
MNT out
(L/R)
SPDIF
OUT
I2S
Dual LVDS
Connector (FHD)
Full HD(1080P)
RS-232C
Dead IC when Standby
Alive IC when Standby
Video
Front
End
Dual
HDMI
Rx
HD/SD
Video
Encoder
Audio
DSP
BCM3552(HD)
BCM3553(FHD)
MCLK
MCLK
HDMI CEC
HDMI CEC(To
Micom
)
To Micom
SDA
SCL
SIF
IF(AT)
Buffer
Digital out
Single LVDS
Connector(HD
)
Digital out
WXGA(768P)
IR & Local KEY
Buffer
Buffer
24C16
AGC CTL (From BCM)
USB2.0
I2S Audio Input
VSB/QAM/NTSC/SIF
AV1
AV2
COMP1
COMP2
CVBS
DDR(32MB)
(4x16x4)
DDR (128MB)
RGB
Y/
Cb
/Cr
HDMI1
HDMI2
HDMI3
AV1
AV2
COMP1
COMP2
RGB
Coaxial
OUT (LG50)
USB
LG30: HD
LG50: FHD
X400
X-tal(24
ß÷
)
NVRAM
24C512
EEPROM
EEPROM
EEPROM
- 24 -
BCM3552
BCM3553
I2C Master
I2C_CH0 (+5.0V)
I2C_CH1 (+5.0V)
I2C_CH2 (+3.3V)
Live
Dead
CH0
CH1
CH2
I2C_CH3 (+3.3V)
CH3
TU1
AT/NT Tuner
TDVF-H051F
[0xC2]
IC403
NVRAM
24LC512
[0xA6]
IC501
DASP
NTP3000
[0X54]
IC407
MICOM
MTV416GMF
[0x50]
IC102
EEPROM
CAT24C08
[0xA0]
IC500
AUDIO S/W
TEA6420D
[0x9A]
IR
a
s
s
’
y
R:0x20
D-eye G:0x70
LG50_only B:0x90
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