LG HT904TA Service Manual page 19

D
YES
Focus on ok?
YES
Track On OK?
YES
Disc Playback?
YES
E
Proper
NO
signals on A, B, C,
D of MT1389MH.
YES
Proper
CD_DVDCT signal on
MT1389MH.
YES
Check CD_DVDCT connection
between AM5890 and
MT1389MH.
Proper
NO
CD_DVDCT signal on
MT1389MH.
YES
Proper
TRACK signal
on MT1389MH.
YES
T+ & T- output
properly?
YES
Check cable connection
on pick-up head.
NO
Check RF signal waveform.
2-0
NO
Check connections between
MT1389MH and pick-up head.
NO
Check the related circuit on
MT1389MH CD_DVDCT.
NO
Check the related circuit on
MT1389MH.
NO
Check the TRACK connection
on MT1389MH and motor driver.
NO
Check the tracking control amp
circuit on motor driver.