Pwm Modulation Check - LG CJ44 Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

5. PWM MODULATION CHECK

PWM MODULATION PART
CHECK
YES
Check
CN102 Pin13, 14
(12 VA)
YES
• Check IC700(TAS5548) VDD 3.3 V - Pin9,14.35,50.
• Check X700 (12.288 MHz).
YES
Check
X700(12.288 MHz)
operation.
YES
Check IC700 Pin21 CLK input.
YES
Check
IC700(TAS5548) input
data Pin24, 25
PWM wave.
YES
Check PWM
modulator output
FL: Pin48(-),49(+)
FR: Pin46(-),47(+).
Other output
check.
YES
OK
NO
Refer to
SMPS troubleshooting.
NO
Check X700
(12.288 MHz).
OK
Check CD
NO
Assy communication
Pin22, 23, 24.
Check
IC700 input
data.
OK
NO
Check IC700.
OK
3-22
NO
YES
NO
YES
NO
YES
YES
NO
YES
Replace X700(12.288 MHz).
Refer to CD troubleshooting.
Check each line resistor output.
Replace IC700.