41
MXD-D400
7. Turn the
l
AMS
L
(MD) knob so that the waveform of
the oscilloscope becomes the specified value.
(When the
l
AMS
L
(MD) knob is turned, the
of
“EFB=
” changes and the waveform changes.) In this ad-
justment, waveform varies at intervals of approx. 2%. Adjust
the waveform so that the specified value is satisfied as much
as possible.
(Write power traverse adjustment)
Traverse Waveform
8. Press the
[YES]
button, and save the adjustment results in the
non-volatile memory. (“EFB =
SAVE” will be displayed
for a moment)
9. “EFB =
MO-P” will be displayed.
The optical pick-up moves to the pit area automatically and
servo is imposed.
10. Turn the
l
AMS
L
(MD) knob until the waveform of
the oscilloscope moves closer to the specified value.
In this adjustment, waveform varies at intervals of approx. 2%.
Adjust the waveform so that the specified value is satisfied as
much as possible.
Traverse Waveform
11. Press the
[YES]
button, and save the adjustment results in the
non-volatile memory. (“EFB =
SAVE” will be displayed
for a moment.)
Next “EF MO ADJUS” (C07) is displayed. The disc stops ro-
tating automatically.
12. Press the
[EJECT]
button and take out the disc.
13. Load the check disc (MD) (TDYS-1).
14. Turn the
l
AMS
L
(MD) knob to display “EF CD
ADJUS” (C08).
15. Press the
[YES]
button to display “EFB =
CD”. Servo is
imposed automatically.
16. Turn the
l
AMS
L
(MD) knob so that the waveform of
the oscilloscope moves closer to the specified value.
In this adjustment, waveform varies at intervals of approx. 2%.
Adjust the waveform so that the specified value is satisfied as
much as possible.
Traverse Waveform
17. Press the
[YES]
button, display “EFB =
SAVE” for a mo-
ment and save the adjustment results in the non-volatile
memory.
Next “EF CD ADJUS” (C08) will be displayed.
18. Press the
[EJECT]
button and take out the disc (MD) (TDYS-
1).
Adjustment Location: BD (MD) board (see page 43)
5-14. FOCUS BIAS ADJUSTMENT
Adjusting Procedure:
1. Load the test disc (MDW-74/GA-1).
2. Turn the
l
AMS
L
(MD) knob to display “CPLAY 2
MODE” (C36).
3. Press the
[YES]
button to display “CPLAY 2MID”.
4. Press the
[MENU/NO]
button when “C =
AD =
” is
displayed.
5. Turn the
l
AMS
L
(MD) knob to display “FBIAS
ADJUS” (C09).
6. Press the
[YES]
button to display “
/
a =
”.
The first four digits indicate the C error rate, the two digits
after “/ ” indicate ADER, and the 2 digits after “a =” indicate
the focus bias value.
7. Turn the
l
AMS
L
(MD) knob clockwise and find the
focus bias value at which the C error rate becomes about 200
(refer to Note 2).
8. Press the
[YES]
button to display “
/
b =
”.
9. Turn the
l
AMS
L
(MD) knob counterclockwise and find
the focus bias value at which the C error rate becomes about
200.
10. Press the
[YES]
button to display “
/
c =
”.
11. Check that the C error rate is below 20 and ADER is 00. Then
press the
[YES]
button.
12. If the “(
)” in “
-
-
(
)” is above 20, press the
[YES]
button.
If below 20, press the
[MENU/NO]
button and repeat the ad-
justment from step 2.
13. Press the
[EJECT]
button and take out the disc.
Note 1:
The relation between the C error and focus bias is as shown in
the following figure. Find points A and B in the following figure
using the above adjustment. The focal point position C is auto-
matically calculated from points A and B.
Note 2:
As the C error rate changes, perform the adjustment using the
average vale.
A
B
VC
Specification A = B
A
B
VC
Specification A = B
A
B
VC
Specification A = B
C error
about
200
B
C
A
Focus bias value
