Sony MDS-JB920 26, Focus Bias Check, C PLAY Checking MO Error Rate Check, CD Error Rate Check

9.Press the [YES] button display “EFB = MO-P”.

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

10.Observe the waveform of the oscilloscope, and check that the specified value is satisfied. Do not rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob.

(Traverse Waveform)

A

VC

B

Specified value : Below 10% offset value

Offset value (%) = IA – BI X 100 2 (A + B)

11.Press the [YES] button display “EF MO CHECK” The disc stops rotating automatically.

12.Press the [ÊÊÊÊÊEJECT]¤ button and remove the disc.

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

14.Roteto the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “EF CD CHECK” (C04).

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

16.Observe the waveform of the oscilloscope, and check that the specified value is satisfied. Do not rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob.

(Traverse Waveform)

A

VC

B

Specified value : Below 10% offset value

Offset value (%) = IA – BI X 100 2 (A + B)

17.Press the [YES] button and display “EF CD CHECK”.

18.Press the [ÊÊÊÊÊEJECT]¤ button and remove the check disc (MD) TDYS-1.

6-4. Focus Bias Check

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

1.Load a test disk (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 = AD = ” is displayed.

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

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

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 220 and ADER is below 2.

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

8.Press the [YES] button and display “ / a = ”. 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 test disc.

6-5. C PLAY Checking

MO Error Rate Check

Checking Procedure :

1.Load a test disk (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 “C = AD = ”.

5.If the C1 error rate is below 80, check that ADER is below 2.

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

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 = AD = ”.

5.Check that the C1 error rate is below 50.

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

6-6. Self-Recording/playback Check

Prepare a continuous recording disc using the unit to be repaired and check the error rate.

Checking Procedure :

1.Insert a recordable disc (blank disc) into the unit.

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “CREC MODE” (C31).

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

4.When recording starts, “ REC ” is displayed, this becomes “CREC @@@@” (@@@@ is the address), and recording starts.

5.About 1 minute later, press the [MENU/NO] button to stop continuous recording.

6.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “C PLAY MODE”(C30).

7.Press the [YES] button to display “C PLAY MID”.

8.“C = AD = ” will be displayed.

9.Check that the C1 error becomes below 80 and the AD error below 2.

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

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