LG MDD64K Service Manual page 20

8. PWM MODULATION PART CHECK
PWM MODULATION
PART CHECK
YES
check P7905 pin9,10
3.3V
YES
Check IC604(PS9830)
VDD pin voltage (3,10,22,29,
39,47,56,65,72,87,94)
check X601 pin2 :3.3V
YES
Check
X601 12.288MHz
operation
YES
check IC604
pin86 CLK input
YES
Check
IC100(LC87Fxx)
pin34:PWM REST
pin86: PWM_DSP_DAT
pin87:PWM_DSP_CLK
output
YES
Check
IC604(PS9830)
pin 23,24,25,26
DATA input,
PWM wave
YES
Check PWM
modulator output
FL:pin75(+),74(-)
FD:pin71(+),70(-)
check other
output
YES
OK
NO
Refer to SMPS
troubleshooting
NO
Check X601
12.288MHz
OK
Check line
resistor output
SDA:R671,SCL:R670
RST:R665
OK
NO
Check P7403
DVD assy communication
Check
NO
IC604(PS9830) DATA
input
OK
NO Check
IC604(PS9830)
OK
3-5
NO
YES
NO
YES
NO
Refer to DVD troubleshooting
YES
NO
YES
NO
YES
Replace X601
Replace R671,R670,R665
Check each line
resistor output
Replace IC604