Sony CDP-68 - Page 8

cDP-68
/207ESD/75,0
Focur
Bias
Adjustment
This
adjustment
should
Optical
pick-up
Block.
hoccdurc:
be made when
replacing
otcilloscope
(DC
rangel
npin bærd
TP
IBF)
fP
(AFG)
l. Connect
oscilloscope
to test
point
TP
(RF)
and
test
point
TP
(RFG).
2. Turn POllrER
switch
on.
3.
Put
disc
(YEDS-I8)
in
and
press
> button.
4.
Adjust
RVl02
for
an
optimum waveform
eye
pat-
tern
or
so that
the
peak
is
maximum.
Optimum
eye
pattern
means
that
shape " O
,'
can be
clearly
distinguished
at
the
center
of
the waveform.
EF
signal waycform
A
-
t.2V
x
0.2
(Vp-p)
Adjustment
Location:
main
board
TP
(A.GI
-e-
TP
(RFI
COMPONENT
SIDE
(FRONT)
FocusÆrack
ing
Gain
Adiustment
A
frequency
response
analyzer
is necessary
in
order to
perform
this
adjustment exactly.
However,
this
gain
has
a
margin,
so
even
if
it is
Nolr
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
adjustrnent
is
at
the
point
where
both
are satisfied.
o
lVhen
gain
is
raised,
the
noise
when
the
2-axis
device
operates
increases.
a
When
gain
is
lowered,
it is
more
susceptible
to
mechanical
shock
and skipping
occurs
more
easily.
a
lilhen
gain
adjustment
is
off,
the
symptoms
below
appear.
2.
lt
3.C
(r
4.4
ill
T
-si
l.
ol
c
Grin
SymptorË
Focur
Træking
o
The time until
music
ataris
becomes
longer
for
STOP
+>PLÂY
or automatic
selection
(li{.
}}lburtons
pressed.
(Normally
takes
about
2
seconds.)
low
low or high
o
Music does not start
and
disc
continues to
rotate
for
STOP+DPLAY
or
automalic
selection
(
l(
)}l
butrons
pressed.)
low
oDisc
rable
opens
shortly
AftCI
STOP+>PLAY.
low
or
high
o
Sound
is interrupted
dur-
ing
PLAY.
Or
lime count-
er
display
stops
progress-
ing.
low
o
More
poise
during
2-axis
device operation.
high high
-8-
af-u