3-7
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
NO
NO
YES
YES
Check the laser power circuit
on 1389DE/LP and connecting
to power transistor.
Check cable connection
between transistor output
and pick-up head
NO
Laser off
NO
NO
YES
Check the related circuit
on RF signal.
Check
DVD_LD & CD_LD signal
YES
YES
NO
NO
YES
Check SPD_PWM related
circuit on 1389DE/LP.
YES
Check the cable connection
between spindle and main PCBA.
YES
YES
Laser
turns on when
reading disc?
DVD_LD,
CD_LD output
properly?
NO
Check the related circuit on
laser power transistor
Collector
voltage of power transistor
is OK?
Put disc in?
Disc ID
is correct?
Does
spindle rotate?
Proper
SPD_PWM signal on
1389DE/LP
NO
Check the spindle control
amp circuit of motor driver
& FAN_SPN output
properly?
Proper RF
signal on OPU
C
D
