LG MDT505 - Laser and Disc Reading Checks

3-13
NO
NO
YES
YES
YES
YES
YES
YES
YES
DVDLD or
CDLD output
property?
NO
NO
Put disc in?
YES
YES
NO
NO
NO
NO
NO
D
C
Disc ID is correct?
Proper
RF signal on
MT1389SE/GH.
Does sPindle rotate?
Proper
SPinDLE signal on
MT1389SE/GH.
SPNP
& SPNN output
properly?
Laser
turns on when
reading disc?
Check the laser power circuit
on MT1389SE/GH and
connecting to power transistor.
(Q400, Q401).
YES
Check cable connection
between transistor output and
pick-up head(23p FFC).
Laser off.
Check the RF connection
between S3053 and MT1389SE/GH.
Check the related circuit on
laser power transistor.
Collector
voltage of power transistor
is OK?(Q400, Q401)
Check the cable connection
between sPindle and main
PCB(15p FFC).
Check the sPindle control amp
circuit of motor driver.
Check the SPinDLE related
circuit on MT1389SE/GH.
Check the related circuit on
MT1389SE/GH RF signal.