LG HT806TGW Service Manual page 62

ELECTRICAL TROUBLESHOOTING GUIDE
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?(Q400, Q401)
YES
Check cable connection
between transistor output and
pick-up head.
NO
Laser off.
Proper
NO
RF signal on
MT1389FE/GH.
YES
Check the RF connection
between S3053 and MT1389FE/GH.
Proper
NO
SPIND signal on
MT1389FE/GH.
YES
SP+
& SP- output
properly?
YES
Check the cable connection
between spindle and main
PCB.
2-51
Check the laser power circuit
NO
on MT1389FE/GH and
connecting to power
transistor.(Q400, Q401)
NO
Check the related circuit on
laser power transistor.
NO
Check the related circuit on
MT1389FE/GH RF signal.
NO
Check the SPIND related
circuit on MT1389FE/GH.
NO
Check the spindle control amp
circuit of motor driver.