LG RAT375 - Power Amp Part Check

3-7
6. PWM MODULATION CHECK
PWM MODULATION PART CHECK
Check
CN105 Pin10 3.7 VA.
• Check IC602(PS9850) VDD 3.3 V
(Pin16,24,29,32,35,40,48,61,64)
• Check VDD Core 1.2 V (Pin1,21,43,57,59,60)
• 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
IC602(PS9850)
Pin51 CLK input.
Check
IC102(LC87Fxx)
Pin41:PWM RESET
Pin45:PWM SDA
Pin46:PWM SCL
output.
NO
Replace R636,R637,R638.
Check line
resistor output
RST: R636 / SCL: R637 /
SDA: R638.
NO
YES
YES
YES
YES
YES
YES
OK
YES