31
MDS-JB980
12. 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.
13. Press the
A
EJECT button and remove the disc.
14. Load the check disc (MD) TDYS-1.
15. Rotate
l
AMS
L
knob and display “EF CD ADJUS”
(C08).
16. Press the YES button and display “EFB =
CD”. Servo is
imposed automatically.
17. Rotate the
l
AMS
L
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)
18. 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.
19. Press the
A
EJECT button and remove the check disc (MD)
TDYS-1.
Note 1 : MO reading data will be erased during if 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.
5-13. FOCUS BIAS ADJUSTMENT
Adjusting Procedure :
1. Load a test disk (MDW-74/GA1).
2. Rotate the
l
AMS
L
knob and display “CPLAY1 MODE”
(C34).
3. Press the YES button and display “CPLAY1 MID”.
4. The display change to “C =
AD =
”.
5. Press the MENU/NO button.
6. Rotate the
l
AMS
L
knob and display “FBIAS ADJUS”
(C09).
7. Press the YES button and 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.
8. Rotate the
l
AMS
L
knob in the clockwise direction and
find the focus bias value at which the C error rate becomes 200
(Refer to Note 2).
9. Press the YES button and display “
/
b =
”.
10.Rotate the
l
AMS
L
knob in the counterclockwise di-
rection and find the focus bias value at which the C error rate
becomes 200.
VC
A
B
Specification A = B
330 k
Ω
Oscilloscope
10pF
BD board
CN105 pin
4
(TE)
CN105 pin
6
(VC)
C error
200
b
c
a
Focus bias value
(F. BIAS)
11. Press the YES button and display “
/
c =
”.
12. Check that the C error rate is below 50 and ADER is 2. Then
press the YES button.
13. If the “(
” in “
-
-
(
” is above 20, press the YES
button.
If below 20, press the MENU/NO button and repeat the
adjustment from step 2.
14. Press the
A
EJECT button to remove the test 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 automatically calculated from points a
and b.
Note 2 : As the C error rate changes, perform the adjustment using
the average vale.
5-14. ERROR RATE CHECK
5-14-1. CD Error Rate Check
Checking Procedure :
1. Load a check disc (MD) TDYS-1.
2. Rotate the
l
AMS
L
knob and display “CPLAY 1MODE”
(C34).
3. Press the YES button twice and display “CPLAY1 MID”.
4. The display changes to “C =
AD =
”.
5. Check that the C error rate is below 50.
6. Press the MENU/NO button, stop playback, press the
A
EJECT
button, and remove the test disc.
5-14-2. MO Error Rate Check
Checking Procedure :
1. Load a continuously recorded test disc (MDW-74/GA1).
(Refer to “5-5. Using the Continuously Recorded Disc”.)
2. Rotate the
l
AMS
L
knob and display “CPLAY 1 MODE”
(C34).
3. Press the YES button and display “CPLAY1 MID”.
4. The display changes to “C =
AD =
”.
5. If the C error rate is below 50, check that ADER is 2.
6. Press the MENU/NO button, stop playback, press the
A
EJECT
button, and remove the test disc.
