LG MICRO Hi-Fi SYSTEM Service Manual page 26

B
YES
Laser turns on
when reading
disc?
YES
Put disc in tray
YES
Does spindle
rotate?
YES
C
NO
DVDLD or CDLD
output properly?
YES
Collector
voltage of power transistor
is ok? (Q405, Q406)
YES
Check cable connection
between P405 and pick-up head
NO
Laser off
NO
Proper spindle
signal on ES8391
YES
SPIN+ & SPIN- output
properly?
YES
Check the cable connection
between P401 and MD
3-13
NO
Check the laser power circuit between
ES8391 and power transistor
(Q405, Q406)
NO
Check the related circuit of laser
power transistor
NO
Check the SPINDLE related
circuit on ES8391
NO
Check the SPINDLE control of
motor driver (IC401)