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•
DR- R504X
4.
Grating Adjustment
(Adjustment
1)
•
Objective
To align the tracking error generation laser beam spots to the optimum angle on the track.
•
Symptom when out of
Play does not start, track search is impossible, tracks are
skipped.,
adjustment
•Measurement instru-
ment connections
[Procedure]
Connect the oscilloscope to
TP201, Pin 2 (TE) via a
low-pass
filter.
(see
Fig.
5)
[Settings]
50 mV/division
5 ms/division
DC mode
•
Player state
Spindle rotation frequency
:
Normal
speed, focus ON, spindle ON/
tracking OFF
•Adjustment location
Grating slit on pickup
•Disc
YEDS-7
1. Move the pickup to the position where the grating adjustment slit will be seen so that the grating adjustment can be
adjusted
.
2.
Set to normal
speed,
focus ON and spindle
ON.
3. Insert a screwdriver into the grating adjustment slit and adjust the grating to find the null point.
For more details, see next
page.
4. Turn the screw driver counterclockwise from the null point and set the grating to the first point where the wave
amplitude reaches its
maximum.
32
Reference
:
Fig.6 shows the relation between the angle of the tracking beam with the track and the
waveform.
Pin 2
(TE)
Pin 4
(AGND)
(10
:
1)
Fig. 5
D
0
0
osmal l
1'~.,,;,.
' '
'
'
(
(
(
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