Sony MDS-JE480 Service Manual Download

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MDS-JE480

11. 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)

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” is displayed. The disc stops rotating
automatically.

13. Press the

EJECT button and remove the disc.

14. Load the check disc (MD) TDYS-1.
15. Rotate

AMS

knob and display “EF CD ADJUST”.

16. Press the YES button and display “EFB =

CD”. Servo is

imposed automatically.

17. 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)

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 ADJUST” will be displayed.

19. Press the

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/GA-1).
2. Rotate the

AMS

knob and display “CPLAY1

MODE”.

3. Press the YES button and display “CPLAY1 MID”.
4. The display change to “C =

AD =

”.

5. Press the MENU/NO button and display “CPLAY1 MODE”.
6. Rotate the

AMS

knob and display “FBIAS AD-

JUST”.

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

AMS

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 “

b =

”.

10.Rotate the

AMS

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 “

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

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.

Specification A = B

330 k

Ω

Oscilloscope

10pF

BD board

CN105 pin

(TE)

CN105 pin

(VC)