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10. Next "EFB =
MO-P" is displaed, the optical pick-up moves
to the internal circumference of the pit and servo is imposed.
11. Rotate the VOLUME knob so that the oscilloscope waveform
becomes the specified value.
The waveform changes by about 2% everytime when adjusted.
Adjust as close as possible to the specified value.
(Traverse Waveform)
VC
Specified value : A = B
12. Press the p (CD) button and save the adjustment results in the
non-volatile memory (displayed as "EFB =
momentarliy).
"EFBAL: CD is next displayed and the disc stops rotating
automatically.
13. Press the 6 (MD) button and remove the disc.
14. Load the check disc (MD) TDYS-1.
15. Press the p (CD) button to display "EFB =
is imposed automatically.
16. Rotate the VOLUME knob so that the oscilloscope waveform
becomes the specified value.
The waveform changes by about 2% everytime when adjusted.
Adjust as close as possible to the specified value.
(Traverse Waveform)
VC
Specified value : A = B
17. Press the p (CD) button and save the adjustment results in the
non-volatile memory after "EFB =
displayed.
"EFBAL ADJUST" is next displayed.
18. Press the 6 (MD) button and remove the check disc (MD)
TDYS-1.
Note 1 : The data will be overwritten on the MO and erased when a
recorded disc is used in this adjustment.
Note 2 : If the traverse waveform is not clear, connect the oscillo-
scope as shown in the following figure so that it can be
seen more clearly.
330 k
BD (MD) board
TP (TEO)
TP (VC)
A
B
SAVE"
CD". The servo
A
B
SAVE" is momentarliy
Oscilloscope
10pF
– 26 –
6-8. FOCUS BIAS ADJUSTMENT
Adjusting Procedure :
1. Load a continuously recorded disc (Refer to 6-4. Creating the
Continuously Recorded Disc").
2. Rotate the VOLUME knob to display "CPLAY MODE".
3. Press the p (CD) button to display "CPLAY MID".
4. When "C1 =
AD =
button.
5. Rotate the VOLUME knob to display "FBIAS ADJUST".
6. Press the p (CD) button to display "
The first four digits indicate the C1 error rate, the two digits
after the "/" indicate ADER and the two digits after "a =" indicate
the focus bias value.
7. Rotate the VOLUME knob in the clockwise direction, and look
for the focus bias value at which the C1 error rate becomes
approximately approx. 200. (Refer to Note 2).
8. Press the p (CD) button to display "
9. Rotate the VOLUME knob in the counterclockwise direction,
and look for the focus bias value at which the C1 error rate
becomes approx. 200.
Check that the C1 error rate becomes almost equal to the value
set in step 7.
10. Press the p (CD) button to display "
11. Check that the C1 error rate is below 50 and that ADER is 00.
and press the p (CD) button.
12. If the value of "( )" in the "
above 20, press the p (CD) button.
If below, press the ^ (CD) button and start from step 2 again.
13. Press the 6 button and remove the continuously recorded disc.
Note 1 : The following figure shows the relation between the C1
error and focus bias value. Look for points a and b in the
following figure by the adjustment avove. The focus
position (point c) is automatically calculated from points
a and b.
Note 2 : As the C1 error rate changes, use the average value in the
adjustment.
C1 error
approx.
200
b
c
" is displayed, press the ^ (CD)
/
a =
".
/
b =
".
/
c =
".
-
-
( )" displayed is
a
Focus bias value
(F. BIAS)
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