Sony MDS-JA20ES - Minidisc Deck, Руководство по обслуживанию

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8. Rotate the
[ AMS ]
knob so that the waveform of the
oscilloscope becomes the specified value.
(When the
[ AMS ]
knob is rotated, the of “EFB-
” changes and the waveform changes.) In this adjustment,
waveform varies at intervals of approx. 2%. Adjust the wave-
form so that the specified value is satisfied as much as pos-
sible.
(Write power traverse adjustment)
(Traverse Waveform)
9. Press the
[YES]
button, and save the adjustment results in the
non-volatile memory. (“EFB = SAV” will be displayed for
a moment.)
10. “EFB = MO-P”. will be displayed.
The optical pick-up moves to the pit area automatically and
servo is imposed.
11. Rotate the
[ AMS ]
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)
12. Press the
[YES]
button, and save the adjustment results in the
non-volatile memory. (“EFB = SAV” will be displayed for
a moment.)
Next “EF MO ADJUS” is displayed. The disc stops rotating
automatically.
13. Press the
§
button and remove the disc.
14. Load the check disc (MD) TDYS-1.
A disc is loaded automatically, if pushing the tray.
15. Roteto
[ AMS ]
knob and display “EF CD ADJUS”
(C12).
16. Press the
[YES]
button and display “EFB = CD”. Servo is
imposed automatically.
17. Rotate the
[ AMS ]
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)
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±
≠
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18. Press the
[YES]
button, display “EFB = SAV” for a mo-
ment and save the adjustment results in the non-volatile
memory.
Next “EF CD ADJUS” will be displayed.
19. Press the
§
button and remove the check disc (MD) TDYS-
1.
5-12. FOCUS BIAS ADJUSTMENT
Adjusting Procedure :
1. Load a test disk (MDW-74/AU-1).
A disc is loaded automatically, if pushing the tray.
2. Rotate the
[ AMS ]
knob and display “CPLAY MODE”
(C30).
3. Press the
[YES]
button and display “CPLAY MID”.
4. Press the
[MENU/NO]
button when “C = AD = ” is
displayed.
5. Rotate the
[ AMS ]
knob and display “FBIAS AD-
JUST” (C13).
6. Press the
[YES]
button and display “ / a = ”.
The first four digits indicate the C1 error rate, the two digits
after [/] indicate ADER, and the 2 digits after [a =] indicate
the focus bias value.
7. Rotate the
[ AMS ]
knob in the clockwise direction
and find the focus bias value at which the C1 error rate be-
comes 220 (Refer to Note 2).
8. Press the
[YES]
button and display “ / b = ”.
9. Rotate the
[ AMS ]
knob in the counterclockwise di-
rection and find the focus bias value at which the C1 error rate
becomes 220.
10. Press the
[YES]
button and display “ / c = ”.
11. Check that the C1 error rate is below 50 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
§
button to remove the test disc.
Note 1:
The relation between the C1 error and focus bias is as
shown in the following figure. Find points a and b in the follow-
ing figure using the above adjustment. The focal point position
C is automatically calculated from points a and b.
Note 2: As the C1 error rate changes, perform the adjustment using the
average vale.
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A
B
VC
Specification A = B
A
B
VC
Specification A = B
A
B
VC
Specification A = B
C1 error
220
b
c a Focus bias value
(F. BIAS)