Sony MDS-PC3 M-crew Service Manual page 32

10. Rotate the AMS knob until 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)
VC
Specification A = B
11. Press the @/1 button, and save the adjustment results in the
non-volatile memory. ("EFB =
a moment.)
Next "EF MO ADJUS (C07)" is displayed. The disc stops ro-
tating automatically.
12. Press the x/Z "PGM" button and remove the disc.
13. Load the check disc (MD) TDYS-1.
14. Roteto AMS knob and display "EF CD ADJUS" (C08).
15. Press the @/1 button and display "EFB =
imposed automatically.
16. Rotate the AMS 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)
VC
Specification A = B
17. Press the @/1 button, display "EFB =
ment and save the adjustment results in the non-volatile memory.
Next "EF CD ADJUST" (C08) will be displayed.
18. Press the x/Z "PGM" 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.
BD board
CN105 pin 4 (TE)
CN105 pin 6 (VC)
32
SAVE" will be displayed for
CD". Servo is
SAVE" for a mo-
Oscilloscope
330 kΩ
10pF
5-13. FOCUS BIAS ADJUSTMENT
Adjusting Procedure :
1. Load a test disk (MDW-74/GA-1).
2. Rotate the AMS knob and display "CPLAY1MODE" (C34).
3. Press the @/1 button and display "CPLAY1 MID".
4. Press the x/Z button when "C =
played.
5. Rotate the AMS knob and display "FBIAS ADJUST" (C09).
6. Press the @/1 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.
B
7. Rotate the AMS knob in the clockwise direction and find the
focus bias value at which the C error rate becomes 200 (Refer to
Note 2).
8. Press the @/1 button and display "
9. Rotate the AMS knob in the counterclockwise direction and
find the focus bias value at which the C error rate becomes 200.
10. Press the @/1 button and display "
11. Check that the C error rate is below 20 and ADER is 00. Then
press the @/1 button.
12. If the "( " in "
button.
If below 20, press the x/Z
adjustment from step 2.
13. Press the x/Z "PGM" 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.
A
C error
B
200
b
AD =
/ a =
/ b =
/ c =
( " is above 20, press the @/1
- -
button and repeat the
c a Focus bias value
(F. BIAS)
)" is dis-
T)".
T".
T)".