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Only for training and service purposes
LGE Internal Use Only
NO
NO
Check the laser power circuit between
ES8390 and power transistor.
(Q405, Q406)
YES
YES
Check cable connection
between PN4401 and pick-up head.
Put disc in SLOT.
Laser turns on
when reading
disc?
YES
YES
DVDLD or CDLD
output properly?
NO
Check the related circuit of laser
power transistor.
YES
Collector
voltage of power transistor
is ok? (Q405, Q406)
NO
NO
Check the SPINDLE related
circuit on SLOT.
NO
Laser off.
Check the cable connection
between PN4401 and MD.
Does SPINDLE
rotate?
YES
YES
YES
Proper SPINDLE
signal on ES8390.
NO
Check the SPINDLE control of
motor driver ES8390.
SPIN+&SPIN- output
properly?
B
C