34
8. Rotate the
l
AMS
L
knob so that the waveform of the
oscilloscope is the specified value. (The figure of the “ EFB
= ” and the waveform are changed by rotating the
l
AMS
L
knob.) In this adjustment. the 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)
9. Press the YES button to save the adjustment results in the non-
volatile memory. (At this time “EFB = SAV” is displayed
for a moment)
10. “EFB = MO-P” appears and the optical pick-up moves to the
internal circumference of the pit area automatically and servo
is imposed.
11. Rotate the
l
AMS
L
knob so that the waveform of the
oscilloscope moves closer to the specified value.
In this adjustment. the 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)
12. Press the YES button to save the adjustment results in the non-
volatile memory. (At this time “EFB = SAV” is displayed
for a moment)
Then, “EF MO ADJUS” (C07) appears and the disc stops
rotating automatically.
13. Press the
A
button to eject the disc.
14. Load a check disc (TDYS-1).
The disc is loaded by pushing the tray.
15. Rotate the
l
AMS
L
knob to display “EF CD ADJUS”
(C08).
16. Press the YES button to display “EFB = CD”. The servo is
imposed automatically.
17. Rotate the
l
AMS
L
knob so that the waveform of the
oscilloscope makes closer to the specified value.
In this adjustment. the waveform varies at intervals of approx.
2%. Adjust the waveform so that the specified value is satisfied
as much as possible.
VC
Specification: A = B
(Traverse waveform)
A
B
VC
Specification: A = B
(Traverse waveform)
A
B
VC
Specification: A = B
(Traverse waveform)
A
B
18. Press the YES button to save the adjustment results in the non-
volatile memory. (At this time “EFB = SAV” is displayed
for a moment)
Then, “EF CD ADJUS” (C08) appears and the disc stops rotating
automatically.
19. Press the
A
button to eject the check disc.
5-12. Focus Bias Adjustment
Adjustment procedure:
1. Load the test disc (MDW-74/GA-1).
The disc is loaded by pushing the tray.
2. Rotate the
l
AMS
L
knob to display “CPLAY1MODE”
(C34).
3. Press the YES button to display “CPLAY MID”.
4. After “C = AD = ” appears, press the MENU/NO
button.
5. Rotate the
l
AMS
L
knob to display “FBIAS CHECK”
(C16).
6. Press the YES button to display “ / a = ”.
The first four digits indicate the C1 error rate, the two digits
after “/” indicate ADER, and the two digits after “a = “ indicate
the focus bias amount.
7. Rotate the
l
AMS
L
knob in the clockwise direction and
find the focus bias amount at which the C1 error rate becomes
approx. 200. (Refer to Note 2.)
8. Press the YES button to display “ / b = ”.
9. Rotate the
l
AMS
L
knob in the counterclockwise
direction and find the focus bias amount at which the C1 error
rate becomes approx. 200. (Refer to Note 2.)
Adjust the
l
AMS
L
knob so that the C1 error rate
becomes almost same value as the value set in step 7.
10. Press the YES button to display “ / c = ”.
11. Confirm that the C1 error rate is below 50 and the ADER is 00
and press the YES button.
12. If “( )” of “ - ( )” is above 20, press the YES
button.
If it is below 20, press the MENU/NO button and perform the
adjustment from the step 2 again.
13. Press the
A
button to eject 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
following 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 value.
C1 error
Approx. 200
b
c
a
Focus bias value
(F. BIAS)
