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CDP-307ESD/950
Focus
Bias
Adjustment
This adjustment should
be
made when
replacing Optical
Pick-up
Block.
oscilloscope
(DC
range)
Procedure
m
ain
board
TP(RF)
'
TP(RFG)
(
1.
Connect
oscilloscope
to test
points
TP(RF)
and
TP
(RF
G).
2.
Turn
POWER
switch
on.
3.
Put
disc
(YEDS —
18)
in
and playback
the 6th
selection.
4.
Adjust
RV104
for
an
optimum waveform
eye
pattern
or so that
the
peak
is
maximum. Optimum
eye pattern
means
that
shape
"O"
can be
clearly
distinguished
at
the center
of
the
waveform.
#
RF
Signal
Reference
Waveform
(eye pattern)
VOLT/DIV
:
200mV
TIME/DIV
:
500nS
When
observing
the
eye
pattern,
set
the oscilloscope
for
AC
range and
raise vertical sensitivity.
Focus/Tracking
Gain
Adjustment
A
frequency
response analyzer
is
necessary
in
order
to
perform
this
adjustment
exactly.
However,
this
gain has
a
margin,
so
even
if
it
is
slightly
off,
there
is
no
problem. Therefore, do not
perform
this
adjustment.
Focus/tracking
gain
determines
the pick
-
up
follow
-
up
(vertical
and
horizontal)
relative to
mechanical
noise
and
mechanical shock
when
the
2-axis
device operate.
However,
as these reciprocate, the
adjustment
is
at
the
point
where
both
are
satisfied.
®
When
gain
is
raised,
the noise
when
the
2
-axis device
operates
increases.
®
When
gain
is
lowered,
it
is
more
susceptible
to
mechanical shock and skipping
occurs
more
easily.
6
When
gain
adjustment
is
off,
the
symptoms
below
appear.
"
'
—
~
—
—
Gain
Symptoms
~~~~
—
—
Focus
Tracking
The
time
until
music
starts
becomes
longer
for
STOP -*>PLAY
or
automatic
selection
(W<
W
buttons
pressed.
(Normally takes about
2
seconds.)
low
low
or
high
Music does
not
start
and
disc
continues
to rotate
for
STOP -*> PLAY
or
auto
-
matic
selection
(W
buttons
pressed.)
-
low
Disc table
opens
shortly
after
STOP-*
>
PLAY.
low
or
high
-
Adjustment
Location
;
main boad
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