Sony MDS-JB920 30, Error Rate Check, Focus Bias Check, Auto Gain Control Output Level Adjustment

Models: MDS-JB920

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13.ERROR RATE CHECK

13.ERROR RATE CHECK

13-1. CD Error Rate Check

Checking Procedure :

1.Load a check disc (MD) TDYS-1.

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “CPLAY MODE” (C30).

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

4.The display changes to “C = 14. FOCUS BIAS CHECK15.AUTO GAIN CONTROL OUTPUT LEVEL ADJUSTMENT– 30 –Manual background AD = Manual backgroundManual background ”.

5.Check that the C1 error rate is below 20.

6.Press the [MENU/NO] button, stop playback, press the [ÊÊÊÊÊEJECT]¤ button, and remove the test disc.

13-2. MO Error Rate Check

Checking Procedure :

1.Load a test disc (MDW-74/AU-1).

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “CPLAY MODE” (C30).

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

4.The display changes to “C1 = Manual backgroundManual backgroundManual backgroundManual background AD = Manual backgroundManual background ”.

5.If the C1 error rate is below 50, check that ADER is 00.

6.Press the [MENU/NO] button, stop playback, press the [ÊÊÊÊÊEJECT]¤ button, and remove the test disc.

14. FOCUS BIAS CHECK

Change the focus bias and check the focus tolerance amount. Checking Procedure :

1.Load a test disc (MDW-74/AU-1).

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “CPLAY MODE” (C30).

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

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

5.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “FBIAS CHECK” (C05).

6.Press the [YES] button and display “ Manual backgroundManual backgroundManual backgroundManual background /Manual backgroundManual background c = Manual backgroundManual background”.

The first four digits indicate the C1 error rate, the two digits after [/] indicate ADER, and the 2 digits after [c =] indicate the focus bias value.

Check that the C1 error is below 50 and ADER is below 2.

7.Press the [YES] button and display “ Manual backgroundManual backgroundManual backgroundManual background /Manual backgroundManual background b = Manual backgroundManual background ”. Check that the C1 error is below 220 and ADER is below 2.

8.Press the [YES] button and display “ Manual backgroundManual backgroundManual backgroundManual background /Manual backgroundManual background a = Manual backgroundManual background”. Check that the C1 error is below 220 and ADER is below 2

9.Press the [MENU/NO] button, next press the [ÊÊÊÊÊEJECT]¤ but- ton, and remove the continuously recorded disc.

Note 1: If the C1 error and ADER are above other than the specified value at points a (step 8. in the above) or b (step 7. in the above), the focus bias adjustment may not have been carried out prop- erly. Adjust perform the beginning again.

15.AUTO GAIN CONTROL OUTPUT LEVEL ADJUSTMENT

Be sure to perform this adjustment when the pickup is replaced. If the adjustment results becomes “Adjust NG!”, the pickup may be faulty or the servo system circuits may be abnormal.

15-1. CD Auto Gain Control Output Level Adjustment

Adjusting Procedure :

1.Insert the check disc (MD) TDYS-1.

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “AG Set (CD)” (C26).

3.When the [YES] button is pressed, the adjustment will be per- formed automatically.

“Complete!!” will then be displayed momentarily when the value is recorded in the non-volatile memory, after which the display changes to “AG Set (CD)”.

4.Press the [ÊÊÊÊÊEJECT]¤ button to remove the disc.

15-2. MO Auto Gain Control Output Level Adjustment

Adjusting Procedure :

1.Insert the reference disc (MDW-74/AU-1) for recording.

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “AG Set (MO)” (C25).

3.When the [YES] button is pressed, the adjustment will be per- formed automatically.

“Complete!!” will then be displayed momentarily when the value is recorded in the non-volatile memory, after which the display changes to “AG Set (MO)”.

4.Press the [ÊÊÊÊÊEJECT]¤ button to remove the disc.

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Sony MDS-JB920 service manual 30, Error Rate Check, Focus Bias Check, Auto Gain Control Output Level Adjustment