LG MDS64V, Service Manual

Page: 20 / 59

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