LG 42PB4DT-UA (CHASSIS:PA72A) (serv.man2) Service Manual ▷ View online
- 39 -
BLOCK DIAGRAM & TROUBLESHOOTING GUIDE
Check MSP4450K (IC202) Power pins
#12, 13, 65, 66(5V), #39(8V)
Check MSP4450K (IC202) inputs
#19(SCK), #20(LRCK), #22(LRCH)
1
2
3
4
5
6
7
8
9
Check Connector P1611
#10(SCK), #12(LRCK), #LRCH(LRCH)
Check LGDT1102F (IC402)
I2S
outputs
R434(LRCK), R435(SCK), R441(LRCH)
Check MSP4450K (IC202) outputs
#4(SCK), #5(LRCK), #6(LRCH), #74(MCLK)
Check NSP2100A (IC401)
PWM output: R804, R805(LEFT), R802, R803(Right)
PWM mask : R1211(3.3V)
Check TAS5122 (IC403) outputs
IC402: #34, 35, 38, 39(Left), #46, 47, 50, 51(Right)
Check Speaker output wafer
P403(Right), P404(Left)
Check Speaker
Check MSP4450K (IC202) outputs
#33(MNT_R_OUT), #34(MNT_L_OUT)
Check MNT_OUT JACK (J101)
Check LGDT1102F (IC402)
SPDIF
outputs
R436(IEC958_OUT)
Check EPM570T144 (IC301)
COMMON SOUND OUT
Check SPDIF out (R1035)
ANALOG OUT
DIGITAL OUT
MONITOR OUT
- 40 -
BLOCK DIAGRAM & TROUBLESHOOTING GUIDE
TV RF NO SOUND
Main
Audio Processor
(MSP4450K)
PWM Modulator
(NSP2100A)
AMP
(TAS5122)
Front Speaker
Monitor Out
Buffer
(MC33078)
ADC
(CS5331A)
NT Tuner
AT/NT Tuner
HD-2
System CPLD
(EPM570T144)
SPDIF Out
(Optical)
SIF
SIF
I2S
L/R
I2S
I2S
SPDIF
- 41 -
BLOCK DIAGRAM & TROUBLESHOOTING GUIDE
Check MSP4450K (IC202) inputs
#67(M_SIF)
Check MSP4450K (IC202) outputs
#36(SC1_R), #37(SC1_L)
Check Connector
P1611(#2)
1
2
3
4
5
6
Check CS5331(IC1000) in/outputs & Power
#7(5V), #5,8(L/R input), #1(LRCH), #2(SCK),
#3(LRCK), #4(MCLK)
Check LGDT1102F(IC402) inputs
R413(LRCH), R414(LRCK), R415(SCK)
Follow the procedure of
COMMON SOUND OUT
7
8
Check NTSC Tuner (TU1302)
#4(33V), #7,18(5V), #16(SIF)
Check
Antenna
Cable
Check MC33078(IC1001) in/outputs & Power
#8(9V), #2, 6(input), #1, 7(output)
9
#4 (MCLK) :
12.288MHz
#3 (LRCK) :
48KHz
#1 (LRCH) : Not
0
Voltage Level
#36 (SCI_R), 37 (SCI_L) : Not
0
Voltage Level, Analog signal
TV RF NO SOUND
Check Connector
P103(#16,#18)
10
- 42 -
BLOCK DIAGRAM & TROUBLESHOOTING GUIDE
DTV NO SOUND
Main
Audio Processor
(MSP4450K)
PWM Modulator
(NSP2100A)
AMP
(TAS5122)
Front Speaker
Monitor Out
MUX CPLD
(EPM570F256)
AT/NT Tuner
HD-2
Main
(LGDT3703)
System CPLD
(EPM570)
SPDIF Out
(Optical)
I2S
TP
SPDIF
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