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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
Check IC(U401)
Check connections between
U203 and pick-up head.
NO
Focus on OK.
Proper
signals on A, B, C, D
of U203
NO
YES
Check the related circuit
on U203 FEO sugnal.
NO
Proper FEO signal
on U203.
YES
YES
Check cable connection
on pick-up head.
Check the
related circuit on U203
NO
Track on OK.
Proper FEO
signal on U203.
NO
Disc is play?
NO
YES
Check the TRSO connection
on U203 and motor dirver.
NO
Properly TRSO
signal on U203.
YES
Check the tracking control
amp circuit on motor driver.
T+ & T-
output properly.
YES
Check RF signal waveform.
YES
YES
C
B
YES
YES