JVC KD-LH7R Service Manual page 22

KD-LH7R
QQ
3 7 63 1515 0
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:
4V
Does the S-search
waveform appear at
IC681 pins "10" and "11"?
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
Tracking Section
When the disc is rotated
at first:
www
Is the tracking error signal
output at IC601 "11"?
Check IC621.
1-22
http://www.xiaoyu163.com
eàYGNg u5•ïVþ•Q
NO
Is the wiring for IC621
(56) ~ (64) correct?
NO
NO
Is 6V or 3V present at
IC681 "4" and "5"?
NO
Check IC681.
NO
Check the circuits in the
vicinity of IC681 pins
"8","9" and "15".
YES
Check the pickup and
its connections.
NO
Is 4V present at IC681
pins "7" and "6" ?
YES
Check the spindle motor
and its wiring.
NO
Check the circuits in the
vicinity of IC601 "19"~"24"
NO
or the pickup
YES
Check the circuit in the
Approx. 1.2 V
x ao
y
. i
YES
http://www.xiaoyu163.com
http://www.xiaoyu163.com
8
YES
Is 3.3V present at
IC681 pin "20"?
Check the vicinity of
IC621.
YES
Check the feed motor
connection wiring.
YES
Q Q
3 6 7 1 3
NO
Is 4V present at IC621
pin "41" ?
Check the vicinity of
IC681.
YES
vicinity of IC601 pins
"2" ~ "12".
u163
.
2 9 9 4 2 8
NO
Check CD 8V
and 5V.
YES
1 5 0 5 8 2 9 9 4
NO
Check IC621 and
IC601.
YES
Check the pickup and
its connections.
m
co
9 9
2 8 9 9