LG DP450G Service Manual page 23

MAIN ELECTRICAL TROUBLESHOOTING GUIDE
A
YES
Focus on OK.
YES
Track on OK.
YES
Disc is play?
YES
B
Proper
NO
signals on A, B, C, D
of MT1389
YES
Proper FEO signal
on MT1389.
YES
Check IC(U401)
NO
Proper FEO signal
on MT1389.
YES
Properly TRSO
signal on MT1389.
YES
T+ & Toutput
properly.
YES
Check cable connection on
pick-up head.
NO
Check RF signal waveform.
3-16
NO
Check connections between
MT1389 and pick-up head.
NO
Check the related circuit
on MT1389 FEO sugnal.
NO
Check the related circuit
on MT1389
NO
Check the TRSO connection
on MT1389 and motor dirver.
NO
Check the tracking control
amp circuit on motor driver.