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DR- R504X
5. OPP
(Tracking Offset) Adjustment
(Adjustment
1)
•Objective
To correct for the variation in the sensitivity of the tracking photodiode.
•Symptom when out of
Play does not start or track search is
impossible.
adjustment
•Measurement
instru-
ment connections
[Procedure]
Connect the oscilloscope to
• Player
state
TP201 (CN601), Pin 2 (TE)
[This connection may be via a
low-pass filter
(39k Q + 1 OOOpF).]
•Adjustment
location
[Settings]
50 mV/division
5 ms/division
DC mode
•Disc
1. Move the pickup to midway across the disc
(R=35mm).
2.
Set to normal
speed,
focus ON and spindle
ON.
Spindle rotation frequency
:
Normal
speed
,
focus
ON,
spindle
ON/
tracking OFF
VR4
(TE.
OFS)
YEDS-7
3.
Line up the bright line (ground) at the center of the oscilloscope screen and put the oscilloscope into DC
mode.
4.
Adjust VR4
(TE.
OFS) so that the positive amplitude and negative amplitude of the tracking error signal at TP201
(CN601)
,
Pin 2
(TE)
are the same (in other words, so that there is no DC
component).
T
AioB
T
A
A=B
j_
GND
1
1
..
GND
J
B
~
~
l
1
When there is a DC
When
there
is no DC
component
component
34
(
(
(
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