LG CM4540 Service Manual

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

LG CM4540 Specifications

General

Bluetooth	Yes
CD Player	Yes
FM Tuner	Yes
USB Playback	Yes
Playable Disc Types	CD, CD-R/RW
Playable File Types	MP3, WMA
Audio Input	3.5mm AUX