Feed Section - JVC KD-LH7R Service Manual

KD-LH7R

Feed Section

Is the voltage output at
IC621 pin "40" 5V or 0V?
YES
Is 4V present at both
sides of the feed motor?
YES
Check the feed motor.
Focus Section
When the lens is
moving:
Does the S-search
waveform appear at
IC681 pins "10" and "11"?
Spindle Section
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
Tracking Section
When the disc is rotated
at first:
Is the tracking error signal
output at IC601 "11"?
Check IC621.
1-22
NO
Is the wiring for IC621
(56) ~ (64) correct?
NO
Is 6V or 3V present at
IC681 "4" and "5"?
Check IC681.
NO
Check the circuits in the
vicinity of IC681 pins
"8","9" and "15".
4V
YES
Check the pickup and
its connections.
NO
Is 4V present at IC681
pins "7" and "6" ?
Check the spindle motor
and its wiring.
NO
Check the circuits in the
vicinity of IC601 "19"~"24"
NO
or the pickup
YES
Approx. 1.2 V
YES
YES
Is 3.3V present at
IC681 pin "20"?
NO
Check the vicinity of
YES
Check the feed motor
connection wiring.
NO
YES
NO
Is 4V present at IC621
pin "41" ?
YES
Check the vicinity of
Check the circuit in the
vicinity of IC601 pins
"2" ~ "12".
NO
Check CD 8V
YES
IC621.
NO
Check IC621 and
YES
IC681.
YES
Check the pickup and
its connections.
and 5V.
IC601.