Sony MDS-JE630 service manual Focus Bias Adjustment

8.Turn the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob so that the waveform of the oscilloscope becomes the specified value.

(When the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob is turned, the of “EFB-

” changes and the waveform changes.) In this adjustment, waveform varies at intervals of approx. 2%. Adjust the wave- form so that the specified value is satisfied as much as pos- sible.

(Write power traverse adjustment)

Traverse Waveform

A

VC

B

Specification A = B

9.Press the [YES] button, and save the adjustment results in the

non-volatile memory. (“EFB = SAV” will be displayed for a moment)

10.“EFB = MO-P” will be displayed.

The optical pick-up moves to the pit area automatically and servo is imposed.

11.Turn the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob until the waveform of the os- cilloscope 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

A

VC

B

Specification A = B

12.Press the [YES] button, and save the adjustment results in the

non-volatile memory. (“EFB = SAV” will be displayed for a moment.)

Next “EF MO ADJUS” is displayed. The disc stops rotating automatically.

13.Press the [ÊÊÊÊÊEJECT]¤ button and take out the disc.

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

15.Turn the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “EF CD ADJUS” (C12).

16.Press the [YES] button to display “EFB = CD”. Servo is imposed automatically.

17.Turn the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± 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

A

VC

B

Specification A = B

18.Press the [YES] button, display “EFB = SAV” for a mo- ment and save the adjustment results in the non-volatile memory.

Next “EF CD ADJUS” will be displayed.

19.Press the [ÊÊÊÊÊEJECT]¤ button and take out the disc.

12. FOCUS BIAS ADJUSTMENT

Adjusting Procedure :

1.Load the continuously-recorded disc. (Refer to 5. Creating Continuously-Recorded Disc)

2.Turn the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “CPLAY MODE” (C29).

3.Press the [YES] button to display “CPLAY MID”.

4. Press the [MENU/NO] button when “C =	AD = ” is
displayed.

5.Turn the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “FBIAS ADJUS” (C13).

6.Press the [YES] button to 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.Turn the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob clockwise and find the focus bias value at which the C1 error rate becomes about 200 (Re- fer to Note 2).

8.Press the [YES] button to display “ / b = ”.

9.Turn the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob counterclockwise and find the focus bias value at which the C1 error rate becomes about 200.

10.Press the [YES] button to display “ / c = ”.

11.Check that the C1 error rate is below 50 and ADER is 00. Then press the [YES] button.

12.If the “( )” in “ - - ()” is above 20, press the [YES] button.

If below 20, press the [MENU/NO] button and repeat the ad- justment from step 2.

13.Press the [ÊÊÊÊÊEJECT]¤ button and take out the 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 auto- matically calculated from points A and B.

Note 2: As the C1 error rate changes, perform the adjustment using the average vale.

C1 error

about 200

B	C	A	Focus bias value
			(F. BIAS)

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