Pwm Modulation Part Check - LG XC62-A0U Service Manual

6. PWM MODULATION PART CHECK

PWM modulation
part check
YES
P7905_PIN9
3.3V checking
YES
Check IC604(PS9829)
VDD PIN voltage(3, 7, 8,
10, 22, 29, 39, 47, 56, 65,
72, 94).
Check X601_PIN2 3.3V.
YES
Check
X601 12.288MHz
operation.
YES
Check IC605_
PIN3 input and PIN2
output.
YES
IC604
(PS9829) PIN86 CLK
input check
YES
Check
IC100(78KOKF2)
21->PWM_CLK
22->PWM_DATA
43->PWM_REST
output.
YES
Check IC604
(PS9829) DATA input.
78 PIN->DATA
79 PIN->CLK
YES
Check PWM
modulator output.
FL:75(+)74(-)
FR:71(+)70(-)
YES
OK
Refer to
NO
SMPS troubleshooting.
NO
Check X601
12.288MHz.
YES
OK
NO
Check IC605_
PIN8 3.3V.
YES
Check IC605_
PIN3 input
YES
Check IC605_
PIN2 output
YES
OK
NO
Check R680
(470Ω) output.
YES
OK
Check
NO
LINE registor output.
DATA:R671, CLK:R670
RST:R665
YES
OK
Check
NO
DVD ASS`Y(PS9829)
communication
(P7403).
YES
Check
IC604(PS9829) DATA
input.
YES
OK
NO
Check IC604(PS9829).
NO
Replace X601.
Check FB614
NO
BEAD input, output and
voltage.
OK
NO
Check X601
2.288MHz
NO
Replace IC605.
NO
Replace R680.
NO
Replace R670, R671
and R665
NO
Refer to
CD troubleshooting.
NO
Check each LINE
registor output.
3-8
NO
Replace FB614
YES
NO
Replace X601.
YES
OK