Sony MDS-JB930 Service Manual page 28

[ AMS ]
8. Turn the ≠ ±
oscilloscope becomes the specified value.
[ AMS ]
(When the ≠ ±
" 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
VC
Specification A = B
[YES]
9. Press the button, and save the adjustment results in the
non-volatile memory. ("EFB =
a moment)
10. "EFB = MO-P" will be displayed.
The optical pick-up moves to the pit area automatically and
servo is imposed.
[ AMS ]
11. Turn the ≠ ±
cilloscope 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
VC
Specification A = B
[YES]
12. Press the button, and save the adjustment results in the
non-volatile memory. ("EFB =
a moment.)
Next "EF MO ADJUS" is displayed. The disc stops rotating
automatically.
[EJECT ]
13. Press the § button and take out the disc.
14. Load the check disc (MD) TDYS-1.
[ AMS ]
15. Turn the ≠ ±
(C12).
[YES]
16. Press the button to display "EFB =
imposed automatically.
[ AMS ]
17. Turn 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
VC
Specification A = B
28
knob so that the waveform of the
knob is turned, the of "EFB-
A
B
SAV" will be displayed for
knob until the waveform of the os-
A
B
SAV" will be displayed for
knob to display "EF CD ADJUS"
CD". Servo is
knob so that the waveform of the
A
B
[YES]
18. Press the button, display "EFB =
ment and save the adjustment results in the non-volatile
memory.
Next "EF CD ADJUS" will be displayed.
[EJECT ]
§
19. Press the button and take out the disc.
12. FOCUS BIAS ADJUSTMENT
Adjusting Procedure :
1. Load the continuously-recorded disc. (Refer to "5. CREAT-
ING CONTINUOUSLY-RECORDED DISC")
[ AMS ]
2. Turn the ±
≠
(C29).
[YES]
3. Press the button to display "CPLAY MID".
[MENU/NO]
4. Press the button when "C =
displayed.
[ AMS ]
5. Turn the
≠ ±
(C13).
[YES]
6. Press the button to display "
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.
[ AMS ]
7. Turn the ≠ ±
bias value at which the C1 error rate becomes about 200 (Re-
fer to Note 2).
[YES]
8. Press the button to display "
[ AMS ]
9. Turn the ≠ ±
focus bias value at which the C1 error rate becomes about 200.
[YES]
10. Press the button to display "
11. Check that the C1 error rate is below 50 and ADER is 00.
[YES]
Then press the button.
12. If the "( )" in " - -
button.
[MENU/NO]
If below 20, press the
justment from step 2.
[EJECT ]
§
13. Press the button and take out the 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 following figure
using the above adjustment. The focal point position C is auto-
matically calculated from points A and B.
Note 2: As the C1 error rate changes, perform the adjustment using the
average vale.
C1 error
about
200
B C
SAV" for a mo-
knob to display "CPLAY MODE"
AD =
knob to display "FBIAS ADJUS"
/ a = ".
knob clockwise and find the focus
/ b = ".
knob counterclockwise and find the
/ c = ".
[YES]
( )" is above 20, press the
button and repeat the ad-
A Focus bias value
(F. BIAS)
" is