LG XC102 Service Manual page 50

1-7. READING OK CHECK #D (= "NO DISC" DISPLAY)
D
Does
SP+ waveform
appear at (IC802
PIN11 and PN802 PIN5)
waveform #4 spindle
motor drive
wave
YES
Check PN802 connector line
YES
Does
spin waveform
NO
appear at (IC802 PIN6)
waveform #4
spindle drive
wave
Defective IC802
NO
Defective PN802 connector
Defective pick up
spindle motor
4-7
NO
YES
Defective IC801