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I
DR-2111, DR-UP124X-5
2. Tracking Error Balance Verification
•Objective
• Symptom when out
of adjustment
To verify that there is no variation in
the
sensitivity of the tracking photo diode.
Play does not start or track search is impossible.
• Measurement
instrument
connections
Connect the oscilloscope to TRK
• Player state
ERR.
(This connection
may be
via a
low
pass filter.)
Test mode, focus
and spindle
servos
closed
and tracking servo
open
[Settings]
[Procedure]
50 m
V/division.
5
mSec/division.
DC mode
• Adjustment location
None
•Disc
YEDS-7
1. Move the pickup to midway across the disc (RJ\A35 mm)
with
the SCAN
FWD
C>I>
or
REV
<l<J
key.
2. Press the [1] +
[TIME]
key,
the [2]
+
[TIME]
key,
then
the [3] + [TIME]
key in that
order to close the focus servo
then
the
spindle servo.
3.
Line up the bright line
(ground) at
the
very
bottom grid line
of
the oscilloscope
screen and
put the oscilloscope into DC
mode.
4. Supposing that
the
positive
amplitude of the tracking
error signal at
TR. ERR
is (A) and
the negative
amplitude is
(B),
the
following expression is satisfied.
TI
A;tB
When
A~8
,
A-8 X
1.
~0
.
5
c
2
When A< 8
,
8-A
X ..!_
~0.5
c
2
3. RF Level Adjustment
c
1
ii
II\
When there
is
a DC
component
•Objective
To
optimize the playback
RF
signal
amplitude.
•
Symptom when
out
of
adjustment
No
play
or no search
TR
REF
• Measurement
instrument
connections
Connect
the
oscilloscope to
TRK
• Player state
ERR.
(This connection may be
via a
low pass
filter.)
[Settings]
50 m VI
division.
• Adjustment location
lOmSec/division.
DC mode
• Disc
[Procedure]
T
A=B
1
J
TR
REF
If\
l
When there
is no
DC
component
Test
mode,
play
VR201
(Laser
power)
YEDS-7
1. Move the pickup to
midway
across the disc
(R=35
mm) with the SCAN
FWD
I
or REV
! key, then press the
[1] + [TIME]
key, the
[2] + [TIME]
key, the
[3] + [TIME]
key,
then the
[4]
+ [TIME] key in that order to close
the
respective servos
and put
the
player into play mode.
2. Line
up
the bright
line
(GND)
at
the very bottom grid line of the ocilloscope
screen
and put the
oscilloscop~
into DC mode.
3. Adjust VR201 (Laser Power) so
that
the RF
signal
amplitude is 1.8
Vp--p±O.l
V.
(Refer
to
the
waveforms of
MOTHER BOARDAssy)
2
1
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