LG CM4520 Service Manual

5. PWM MODULATION CHECK
PWM MODULATION PART CHECK
Check
CN105 Pin11 3.7 VA.
• Check IC601(PS9854) VDD 3.3 V
(Pin16, 25, 30, 33, 37, 42, 50, 64, 67)
• Check VDD Core 1.2 V (Pin1, 22, 45, 60,63)
• Check X602(19.2 MHz)
NO
Refer to
SMPS troubleshooting.
Check
X602(19.2 MHz)
operation.
NO
Replace X602(19.2 MHz).
Check X602
(19.2 MHz).
OK
YES
NO
Check
IC601(PS9854)
Pin54 CLK input.
Check
IC102(LC87Fxx)
Pin41:PWM RESET
Pin45:PWM SDA
Pin46:PWM SCL
output.
NO
Replace R660,R659,R658.
Check line
resistor output
RST: R660 / SCL: R659 /
SDA: R658.
NO
YES
YES
YES
YES
YES
YES
OK
YES
A
3-22
AUDIO ELECTRICAL TROUBLESHOOTIHG GUIDE

LG CM4520 Specifications

General

Brand	LG
Model	CM4520
Category	Stereo System
Language	English