Sony MDS-S50 - Manual (Page 27)

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MDS-S50
9. Press the [YES] button to 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 turn the [ AMS ]
knob.
Traverse Waveform
11. Press the [YES] button to display “EF MO CHECK” (C14).
The disc stops rotating automatically.
12. Press the Z button and take out the disc.
13. Load the check disc (TDYS-1).
14. Turn the
[ AMS ] knob to display “EF CD CHECK”
(C15).
15. Press the [YES] button to display “EFB = CD”. Servo is
imposed automatically.
16. Observe the waveform of the oscilloscope, and check that the
specified value is satisfied. Do not turn the [ AMS ]
knob.
Traverse Waveform
17. Press the [YES] button to display “EF CD CHECK” (C15).
18. Press the Z button and take out the check disc (TDYS-1).
Checking Location: BD board (see page 32)
5-6-7. Focus Bias Check
Change the focus bias and check the focus tolerance amount.
Procedure:
1. Load the test disc (MDW-74/GA-1).
2. Turn the
[ AMS ] knob to display “CPLAY1MODE”
(C34).
3. Press the [YES] button to display “CPLAY1MID”.
4. Press the [MENU/NO] button when “C = AD = )” is
displayed.
5. Turn the [ AMS ] knob to display “FBIAS CHECK”
(C16).
6. Press the [YES] button to 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 20 and ADER is below 2.
7. Press the [YES] button to display “ / b = ”.
Check that the C1 error is about 100 and ADER is below 2.
8. Press the [YES] button to display “ / a = ”.
Check that the C1 error is about 100 and ADER is below 2.
9. Press the [MENU/NO] button, then press the Z button and take
out the test disc (MDW-74/GA-1).
5-6-8. C PLAY Check
MO Error Rate Check
Procedure:
1. Load the test disc (MDW-74/GA-1).
2. Turn the
[ AMS ] knob to display “CPLAY1MODE”
(C34).
3. Press the [YES] button to display “CPLAY1MID”.
4. The display changes to “C = AD = )”.
5. If the C1 error rate is below 20, check that ADER is 00.
6. Press the
[MENU/NO] button to stop playback, then press
the Z button and take out the test disc (MDW-74/GA-1).
CD Error Rate Check
Procedure:
1. Load the check disc (TDYS-1).
2. Turn the
[ AMS ] knob to display “CPLAY1MODE”
(C34).
3. Press the [YES] button to display “CPLAY1MID”.
4. The display changes to “C = AD = )”.
5. Check that the C1 error rate is below 20.
6. Press the
[MENU/NO] button to stop playback, then press
the Z button and take out the check disc (TDYS-1).
5-6-9. Self-Recording/playback Check
Prepare a continuous recording disc using the unit to be repaired
and check the error rate.
Procedure:
1. Load a recordable disc (blank disc).
2. Turn the
[ AMS ] knob to display “CREC 1MODE”
(C35).
3. Press the [YES] button to display “CREC 1MID”.
4. When recording starts, lights up “ REC ” and display “CREC
1 @@@@” (@@@@ is the address).
5. About 1 minute later, press the [MENU/NO] button to stop
continuous recording.
6. Turn the [ AMS ] knob to display “CPLAY1MODE”
(C34).
7. Press the [YES] button to display “CPLAY1MID”.
8. “C = AD = )” will be displayed.
9. Check that the C1 error becomes below 20 and the AD error
below 2.
10. Press the [MENU/NO] button to stop playback, then press
the Z button and take out the disc.
A
B
VC
Specified value : Below 10% offset value
Offset value (%) = X 100
I A – B I
2 (A + B)
A
B
VC
Specified value : Below 10% offset value
Offset value (%) = X 100
I A – B I
2 (A + B)
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