LG FAS166F - Pwm Modulation Check

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ELECTRICAL TROUBLESHOOTING GUIDE
8. PWM MODULATION CHECK
PWM modulation
part check
Refer to
SMPS troubleshooting.
Replace X601.
Replace IC703.
Check IC701(PS9851)
VDD Pin voltage(16,24,29,32,35,40,48).
Check X601 Pin2: 3.3 V.
Check IC701 Pin51 CLK input.
Replace related resistor.
Replace IC500.
Replace IC701.
Check
CN700 Pin1
5 V.
Check
X700 19.2 MHz
operation.
NO
NO
NO
NO
NO
NO
Check
line resistor output
SDA: R153, SCL: R155,
RST: R131.
Check
IC500 DVD MPEG
I2S output.
Check
IC701(PS9851).
IC101
Pin38: PWM RESET
Pin85: PWM SDA
Pin84: PWM SCL
output
Check
IC701(PS9851) data input
Pin14 PWM wave.
Check
PWM modulator output
FL:Pin27(+),28(-) FR:Pin30(+),31(-)
other output
NO
NO
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
OK
OK
OK
OK