Sony MDS-JE480 Service Manual page 33

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11. Rotate the l AMS L 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
12. Press the YES button, and save the adjustment results in the
non-volatile memory. ("EFB =
a moment.)
Next "EF MO ADJUS" is displayed. The disc stops rotating
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 ADJUST".
16. Press the YES button and display "EFB =
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.
TE
L 13942296513
(Traverse Waveform)
VC
Specification A = B
18. Press the YES button, display "EFB =
ment and save the adjustment results in the non-volatile memory.
Next "EF CD ADJUST" 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.
BD board
CN105 pin 4 (TE)
CN105 pin 6 (VC)
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SAVE" will be displayed for
CD". Servo is
SAVE" for a mo-
Oscilloscope
330 kΩ
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5-13. FOCUS BIAS ADJUSTMENT
Adjusting Procedure :
1. Load a test disk (MDW-74/GA-1).
2. Rotate the l AMS L knob and display "CPLAY1
MODE".
3. Press the YES button and display "CPLAY1 MID".
4. The display change to "C =
5. Press the MENU/NO button and display "CPLAY1 MODE".
6. Rotate the l AMS L knob and display "FBIAS AD-
A
JUST".
7. Press the YES button and display "
The first four digits indicate the C error rate, the two digits after
B
[/] 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 220
(Refer to Note 2).
9. Press the YES button and display "
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 220.
11. Press the YES button and display "
12. Check that the C error rate is below 50 and ADER is 2. Then
press the YES button.
13. If the "( " in "
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
Q Q
3 6 7 1 3 1 5
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.
A
Note 2 : As the C error rate changes, perform the adjustment using
the average vale.
B
C error
220
b
co
.
MDS-JE480
9 4 2 8
AD = ".
/ a =
/ b =
/ c =
- - ( " is above 20, press the YES
0 5 8 2 9 9 4 2 8
c a Focus bias value
(F. BIAS)
m
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".
".
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