38
11. Press the
.
or
>
button until the waveform of the oscil-
loscope 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
7
button, and save the adjustment results in the
non-volatile memory. (“EFB =
SAVE” will be displayed for
a moment.)
Next “EF MO ADJUS” is displayed. The disc stops rotating
automatically.
13. Press the
A
button and remove the disc.
14. Load the check disc (MD) TDYS-1.
15. Press the
.
or
>
button and display “EF CD ADJUS” .
16. Press the
7
button and display “EFB =
CD”. Servo is
imposed automatically.
17. Press the
.
or
>
button 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
7
button, display “EFB =
SAVE” for a moment
and save the adjustment results in the non-volatile memory.
Next “EF CD ADJUS” will be displayed.
19. Press the
A
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/GA-1).
2. Press the
.
or
>
button and display “CPLAY2MODE”.
3. Press the
7
button and display “CPLAY2MID”.
4. Press the
x
button when “C1 =
AD =
” is displayed.
5. Press the
.
or
>
button and display “FBIAS ADJUS” .
6. Press the
7
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. Press the
.
or
>
button in the clockwise direction and
find the focus bias value at which the C1 error rate becomes 220
(Refer to Note 2).
8. Press the
7
button and display “
/
b =
”.
9. Press the
.
or
>
button in the counterclockwise direc-
tion and find the focus bias value at which the C1 error rate
becomes 220.
10. Press the
7
button and display “
/
c =
”.
11. Check that the C1 error rate is below 20 and ADER is 00. Then
press the
7
button.
12. If the “(
” in “
-
-
(
” is above 20, press the
7
button.
If below 20, press the
x
button and repeat the
adjustment from step 2.
13. Press the
A
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
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 us-
ing the average vale.
VC
A
B
Specification A = B
VC
A
B
Specification A = B
330 k
Ω
Oscilloscope
10pF
BD board
CN105 pin
4
(TE)
CN105 pin
6
(VC)
C1 error
220
b
c
a
Focus bias value
(F. BIAS)
