Pwm Modulation Check - LG CM4550 Service Manual

AUDIO ELECTRICAL TROUBLESHOOTIHG GUIDE

5. PWM MODULATION CHECK

PWM MODULATION PART CHECK
YES
Check
CN501 Pin7,8
(5.6 V)
YES
• Check IC601(TAS5548)
VDD 3.3 V - Pin9,14.35,50.
• Check X601 (12.288 MHz).
YES
Check
X601(12.288 MHz)
operation.
YES
Check
IC601 Pin21 CLK
input.
YES
Check IC501
(MLC3730)
Pin B3: RESET
Pin A1: SDA
Pin A2: SCL
output.
YES
A
NO
Refer to
SMPS troubleshooting.
NO
Check X601
(12.288 MHz).
YES
OK
Check line
NO
resistor output
RST: R53E / SCL: R53C /
SDA: R53B.
YES
OK
3-22
NO
Replace X601(12.288 MHz).
NO
Replace R53E,R53C,R53B.