Pioneer PD-J400T User Manual

2. Grating adjustment
@
Objective
To
align
the
tracking
error
generation
laser
beam
spots
to
the
optimum
angle
on
the
track.
@ Symptom when out of
adjustment
Play
does
not
start,
track
search
is
impossible,
tracks
are
skipped.
@ Measurement instrument
connections
Connect the oscilloscope to TP1, Pin
2 (TRK ERR) via a low pass filter.
(See Figure 2)
@ Player state
Test mode, focus and spindle
servos closed and tracking servo
open
[Settings] 50 mVidivision
5 ms/division
DC mode
@
Adjustment
location
Pickup
grating
adjustment
slit
12 cm disc.
(YEDS-7 can not be used.)
[Procedure]
1.
Move
the
pickup
to
the
outer
edge
of
the
disc
with
the
MANUAL/TRACK
SEARCH
FWD
p>
/
RI
or
REV
Kil
/
<i
_
key
so
that
the
grating
adjustment
slit
is
at
the
outer
edge
of
the
disc
where
it
can
be
adjusted.
2.
Press
the
PROGRAM
key,
then
the
PLAY
/PAUSE
>
/
[lf
key
in
that
order
to
close
the
focus
servo
then
the
spindle
servo.
3,
Insert
an
ordinary
screwdriver
into
the
grating
adjustment
slit
and
adjust
the
grating
to
find
the
null
point.
For
more
details,
see
the
next
page.
4.
If
you
slowly
turn
the
screwdriver
counterclockwise
from
the
null
point,
the
amplitude
of
the
wave
gradually
increases,
then
if
you
continue
turning
the
screwdriver,
the
amplitude
of
the
wave
becomes
smaller
again,
Turn
the
screwdriver
counterclockwise
from
the
null
point
and
set
the
grating
to
the
first
point
where
the
wave
amplitude
reaches
its
maximum.
Reference:
Figure
3
shows
the
relation
between
the
angle
of
the
tracking
beam
with
the
track
and
the
waveform.
Note:
The
amplitude
of
the
tracking
error
signal
is
about
3
Vp-p
(when
a
39
kQ
+
0.001
LF
low
pass
filter
is
used).
If
this
amplitude
is
extremely
small
(2
Vp-p
or
less),
then
the
objective
lens
or
the
pickup
malfunction
may
be
the
cause.
If
the
difference
between
the
amplitude
of
the
error
signal
at
the
innermost
edge
and
outermost
edge
of
the
disc
is
more
than
10%,
the
grating
is
not
adjusted
to
the
optimum
point,
so
adjust
it
again.
5.
Return
the
pickup
to
more
or
less
midway
across
the
disc
with
the
MANUAL/TRACK
SEARCH
REV
Kf
/
<#
key,
press
the
PLAY/PAUSE
}>/[
key
and
check
that
the
track
number
and
elapsed
time
are
displayed
on
the
front
panel.
If
they
are
not
displayed
at
this
time
or
the
elapsed
time
changes
irregularly,
check
the
null
point
and
adjust
the
grating
again.
2 PIN
(TRK ERR)
Figure 2
Adjustment Locations
29

Pioneer PD-J400T Specifications

General

Brand	Pioneer
Model	PD-J400T
Category	CD Player
Language	English