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Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
MAIN ELECTRICAL TROUBLESHOOTING GUIDE
3. SERVO CIRCUIT
Check IC(U4)
Check connections between
MT1389P and pick-up head.
NO
Focus on OK.
Proper
signals on A, B, C, D
of MT1389P.
NO
YES
Check the related circuit
on MT1389P FEO sugnal.
NO
Proper
FEO signal on
MT1389P.
YES
YES
Check cable connection
on pick-up head.
Check the related
circuit on MT1389P
NO
Track on OK.
Proper
FEO signal on
MT1389P.
NO
Disc is play?
NO
YES
Check the TRSO connection
on MT1389P and motor dirver.
NO
Properly
TRSO signal on
MT1389P.
YES
Check the tracking control
amp circuit on motor driver.
T+ & T-
output properly.
YES
YES
B
YES