LG LH-T3520X Service Manual page 17

C
YES
Laser turns on when
reading disc?
YES
Put disc in?
YES
Disc ID is correct?
YES
Does spindle rotate?
YES
D
DVDLD or
NO
CDLD output
property?
YES
Collector
voltage of power transistor
is OK?(Q401, Q402)
YES
Check cable connection
between transistor output and
pick-up head.
NO
Laser off.
NO Proper
RF signal on MT1389/L.
YES
Check the RF connection
between AM5890 and MT1389/L.
Proper
NO
SPINDLE signal on
MT1389/L.
YES
SPNP
SPNN output
properly?
YES
Check the cable connection
between spindle and main
PCB.
2-8
Check the laser power circuit
NO
on MT1389/L and connecting
to power transistor.
(Q401, Q402).
NO
Check the related circuit on
laser power transistor.
NO
Check the related circuit on
MT1389/L RF signal.
NO
Check the SPINDLE related
circuit on MT1389/L.
NO
Check the spindle control amp
circuit of motor driver.