LG DK763X, Service Manual

Page: 18 / 51

3-7
C
LD01 or LD02 output
properly? Laser turns on when
reading disc?
Put disc in?
Disc ID is correct?
Does spindle rotate?
D
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
Check the laser power circuit
on MT1389E and connecting
to power transistor.
NO
Collector voltage of
power transistor is OK? Check the related circuit on
laser power transistor
NO
Check cable connection
between transistor ouput
and pick-up head.
YES
YES
YES
Check the related circuit
on MT1389E RFL signal.
Check DMSO related
circuit on MT1389E.
NO
NO
Check the spindle control
amp circuit of motor driver.
NO
Laser off
Proper RFL signal on
MT1389E?
Check LDO1 & LDO2 signal
Proper DMSO signal on
MT1389E
SP+ & SP- output properly?
Check the cable connection
between spindle and main
PCBA.