Troubleshooting - JVC KD-G401 Service Manual

5.1 Feed section
Is 5v or 0V at IC541
pin 40?
YES
Is 4V present at both
sides of the feed motor?
YES
Check the feed motor.
5.2 Focus section
5.3 Spindle section
Is the disk rotated?
YES
Does the RF signal
appear at RF test point?
YES
Is the RF waveform
at RF test point distorted?
YES
Proceed to the Tracking
section
5.4 Tracking section
When the disc is rotated
at first:
Is the tracking error
signal output at IC521
pin 11?
Check IC541.
SECTION 5

TROUBLESHOOTING

NO
Is the wiring for IC541
pin 40 correct?
NO
NO
Is 6V or 2V present at
IC501 pins 4 and 5?
NO
Check IC501.
When the lens is
moving:
4V
Does the S-search
waveform appear at
IC501 pins 8 and 9?
YES
NO
Is 4V present between
IC501 pins 6 and 7?
YES
Check the spindle motor
and its wiring.
NO
Check the circuits in
the vicinity of IC521
or the pickup.
NO
Check the circuits in
NO
the vicinity of IC521
pins 2 to 12.
Approx. 1.2V
YES
YES
Is 5V present at IC501
pin 20?
YES
Check the vicinity of
IC541.
YES
Check the feed motor
connection wiring.
Check the circuits in
NO
the vicinity of IC501
pins 15 and 16.
YES
Check the pickup and
its connections.
NO
Is 4V present at IC541
pin 41?
YES
Check the vicinity of
IC501.
NO
Check the pickup and
its connections.
NO
Check 8V.
NO
Check IC541.
(No.MA051)1-25