Troubleshooting - JVC KD-LH911 Servise Manual

QQ
3 7 63 1515 0
5.1 Feed section
Is 5V or 0V at IC621
pin 40?
YES
Is 4V present at both
sides of the feed motor?
YES
Check the feed motor.
5.2 Focus section
TE
L 13942296513
5.3 Spindle section
Is the disk rotated?
YES
Does the RF signal
appear at IC601 pin 19?
YES
Is the RF waveform
at IC601 pin 19 distorted?
YES
Proceed to the Tracking
section
5.4 Tracking section
When the disc is rotated
at first:
Is the tracking error
www
signal output at IC601
pins 10 and 11?
.
Check IC621.
1-26 (No.MA157)
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SECTION 5

TROUBLESHOOTING

NO
Is the wiring for IC621
pin 40 correct?
NO
NO
Is 6V or 2V present at
IC681 pins 17 and 18?
NO
Check IC681.
When the lens is
moving:
4V
Does the S-search
waveform appear at
IC681 pins 13 and 14?
YES
NO
Is 4V present between
IC681 pins 15 and 16?
YES
Check the spindle motor
and its wiring.
NO
Check the circuits in
the vicinity of IC601
or the pickup.
NO
Check the circuits in
NO
the vicinity of IC601
pins 2 to 7.
Approx. 1.2V
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y
YES
i
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2 9
8
YES
Is 5V present at IC681
pin 6?
YES
Check the vicinity of
IC621.
YES
Check the feed motor
connection wiring.
Check the circuits in
NO
the vicinity of IC681
pins 1 and 2.
YES
Check the pickup and
Q Q
3 6 7 1 3 1 5
its connections.
NO
Is 4V present at IC621
pin 41?
YES
Check the vicinity of
IC681.
NO
Check the pickup and
its connections.
co
.
9 4 2 8
NO
Check CD8V.
0 5 8 2 9 9 4 2 8
NO
Check IC621.
m
9 9
9 9