LG DP372D Service Manual page 18

C
Laser
turns on when
reading disc?
YES
Put disc in?
YES
Disc ID
is correct?
YES
Does
spindle rotate?
YES
D
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DVD_LD,
NO
CD_LD output
properly?
Collector
voltage of power transistor
is OK?
Check cable connection
between transistor output
and pick-up head
NO
Laser off
NO
Proper RF
signal on OPU
Check
DVD_LD & CD_LD signal
Proper
NO
SPD_PWM signal on
1389P
FAN_SPN+
& FAN_SPN- output
properly?
Check the cable connection
between spindle and main PCBA.
3-7
NO
circuit on 1389P and connecting
YES
NO
YES
NO
YES
NO
YES
NO
YES
Check the laser power
to power transistor.
Check the related circuit on
laser power transistor
Check the related circuit
on RF signal.
Check SPD_PWM related
circuit on 1389P.
Check the spindle control
amp circuit of motor driver
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