JVC KD-S790 Service Manual page 24

KD-S790
QQ
3.2 Troubleshooting 3 7 63 1515 0
3.2.1 Feed section
Is the voltage output at
IC521 pin u 5V or 0V?
YES
Is 4V present at both
sides of the feed motor?
YES
Check the feed motor.
3.2.2 Focus section
3.2.3 Spindle section
TE
L 13942296513
Is the disk rotated?
YES
Does the RF signal
appear at TP1?
YES
Is the RF waveform at TP1
distorted?
YES
Proceed to the Tracking
section
3.2.4 Tracking section
When the disc is rotated
at first:
www Is the tracking error
signal output at TP3?
Check IC521.
1-24 (No.49788)
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NO
Is the wiring for IC521
(90) ~ (100) correct?
NO
Is 6V or 2V present at
IC581 Q and R?
NO
Check IC581.
When the lens is
moving:
4V
Does the S-search
waveform appear at
IC581 pins H and I?
NO
Is 4V present between
IC581 pins 1 and 2?
Check the spindle motor
and its wiring.
NO
Check the circuits in the
vicinity of IC501 J O or
NO
the pickup
Check the circuit in the
YES
Approx. 1.2V
x ao
y
YES
. i
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8
YES
Is 5V present at IC581
pin 6?
Check the vicinity of
IC521.
YES
Check the feed motor
connection wiring.
NO
Check the circuits in
the vicinity of IC581
pins H
Check the pickup and
its connections .
YES
Q Q
3 6 7
NO
Is 4V present at IC521
pin x?
Check the vicinity of
IC581.
YES
vicinity of IC501 pins
~ 2C .
u163
2 9 9 4
NO
Check CD 9V
and 5V.
YES
K.
YES
1 3 1 5 0 5 8 2 9
NO
Check IC501 and
YES
Check the pickup and
its connections
m
co
.
2 8
9 9
9 4 2 8 9 9
IC521.