Cd Function Check - LG OK75 Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

8. CD FUNCTION CHECK

CD FUNCTION
YES
Can the
disc insert?
YES
Disc reading
is ok?
YES
Is no signal at speaker?
YES
Check
the signal of IC401.
YES
Check
the signal (16.9344 MHz)
at IC401 pin49.
YES
Check IC501
input/output and
control line.
YES
Refer to function check.
NO
Is load +,- ok?
Is motor ok? (about 12 Ω)
NO
IM driving
(Focus and tracking) is ok?
NO
Check Vcc of IC401.
NO
Check cristal (X400).
NO
Replace IC501.
3-32
NO
YES
NO
NO
NO
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Is motor_open/close ok?
(IC400 pin6, 7)
YES
Check IC400.
Check loading motor.
Check IC400 (Motor drive IC).
NO
Focus,
tracking, sled signal
is ok?
YES
Is the MD (PN401 pin22)
about 190 mV?
NO
Check MD (pick-up).
Replace cristal (X400).
Only for training and service purposes.