LG MICRO Hi-Fi SYSTEM Service Manual page 20

YES
Check IC604 PS9831
86pin CLK input
YES
Check
output of IC100
LC87F5NC8A
87→PWM_CLK
86→PWM_DATA
34→PWM_REST
YES
Check IC604
PS9831 data input
78 PIN→DATA
79 PIN→CLK
96 PIN→REST
YES
Check
PWM modulator output
FL:75(+)74(-)
FR:71(+)70(-)
YES
OK
Check R666(1M) output
NO
YES
OK
Check
resistance output of line
NO
DATA:R103
CLK:R141
RST:R152
YES
OK
Check DVD
NO
ASS`Y PS9831
communication condition
(P7403)
YES
Check IC604
PS9831 data input
YES
OK
NO
Check IC604 PS9831 part
3-7
Replace the related part
NO
NO
Replace the related part
NO
Refer to DVD troubleshooting
Check resistance
NO
output of each line