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-
DR- R504X
12. VCO free-run frequency verification
•Objective
To
verify
the VCO free-run frequency is
optimized.
•Symptom when out of
No play and
track search
is
in
possible.
adjustment
•Measurement
instru-
ment connections
(Procedure]
Connect the
foscilloscope
to
TP202
(CN609) , pin 2
(PLLCN)
[Settings]
0.1 V/division
5
ms/division
DC mode
• Player state
•Adjustment location
•Disc
(Adjustment
2)
Spindle rotation
frequency
: Normal
speed•Fourfold speed, focus ON,
spindle ON/tracking ON
L603 (VCO ADJ)
YEDS-7
l
.
In the normal
speed,
focus
ON,
spindle
ON and
tracking
ON
-state, verify
the
center value (center value which is the
thick
portion of
line)
of waveform's
DC
elements at TP202
(CN609),
pin 2 (PLLCN)
is OV
±
O.lV.
2.
In
the fourfold speed, focus
ON,
spindle
ON
and tracking
ON
state, verify the center value
of
waveform's DC elements
at
TP202
(CN609),
pin 2 (PLLCN) is OV
±
0.1 V.
3.
If
the
specified
values cannot
be
obtained, perform the verification after adjusting the
section
"1.
VCO free-run
frequency adjustment"
in (Adjustment 2)
again.
13. WBL Offset Adjustment
•Objective
To optimize
the
DC offset voltage
of
the wobble amp.
•Symptom
when
out of
CD- R disc does not record and
playback.
adjustment
•Measurement
instru-
ment connections
[Procedure]
Connect the
oscilloscope
to
TP2
(CN104),
Pin
5
(WBL).
[This
connection
may
be via a
high-pass filter
(180pF+39.0kQ ).]
[Settings]
100 mV/division
5
ms/division
DC mode
l. Move
the
pickup to the midway
across
the
disc.
• Player
state
•Adjustment location
•Disc
2. Set
to the normal
speed, focus
ON,
spindle
ON
and
tracking ON
state.
(Adjustment
2)
Spindle rotation frequency
:
Normal
speed, focus ON, spindle
ON,
tracking ON
VRl (WBL. OFS)
CDR disc with
recorded
(Type No. CD
-
R63, manufactured
by
TDK.)
3.
Adjust VRl (WBL. OFS)
so
that the
amplitude
of
the
waveform becomes
minimum.
44
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(
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