Sony MDS-JB730 Service Manual page 25

[YES]
9. Press the button to display "EFB =
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
knob.
Traverse Waveform
VC
Specified value : Below 10% offset value
Offset value (%) =
[YES]
11. Press the button to display "EF MO CHECK"
The disc stops rotating automatically.
[EJECT ]
12. Press the § button and take out the disc.
13. Load the check disc (MD) TDYS-1.
[ AMS ]
≠ ±
14. Turn the knob and display "EF CD CHECK"
(C04).
[YES]
15. Press the button to display "EFB =
imposed automatically.
16. Observe the waveform of the oscilloscope, and check that the
specified value is satisfied. Do not turn the
knob.
Traverse Waveform
VC
Specified value : Below 10% offset value
Offset value (%) =
[YES]
17. Press the button to display "EF CD CHECK".
[EJECT ]
18. Press the § button and take out the check disc.
MO-P".
[ AMS ]
≠ ±
A
B
I A – B I
X 100
2 (A + B)
CD". Servo is
[ AMS ]
±
≠
A
B
I A – B I
X 100
2 (A + B)
6-4. Focus Bias Check
Change the focus bias and check the focus tolerance amount.
Checking Procedure :
1. Load the test disk (MDW-74/AU-1).
[ AMS ]
2. Turn the ≠
(C30).
[YES]
3. Press the button twice to display "CPLAY MID".
[MENU/NO]
4. Press the
displayed.
[ AMS ]
≠
5. Turn the
(C05).
[YES]
6. Press the button to display "
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.
[YES]
7. Press the button to display "
Check that the C1 error is about 200 and ADER is below 2.
[YES]
8. Press the button to display "
Check that the C1 error is about 200 and ADER is below 2.
[MENU/NO]
9. Press the
ton and take out the test disc.
6-5. C PLAY Checking
MO Error Rate Check
Checking Procedure :
1. Load the test disk (MDW-74/AU-1).
[ AMS ]
2. Turn the ≠
(C30).
[YES]
3. Press the button to display "CPLAY MID".
4. The display changes to "C =
5. If the C1 error rate is below 80, check that ADER is below 2.
[MENU/NO]
6. Press the
[EJECT ]
§
button and take out the test disc.
CD Error Rate Check
Checking Procedure :
1. Load the check disc (MD) TDYS-1.
[ AMS ]
≠
2. Turn the
(C30).
[YES]
3. Press the button twice to display "CPLAY MID".
4. The display changes to "C =
5. Check that the C1 error rate is below 50.
[MENU/NO]
6. Press the
[EJECT ]
§ button and take out the check 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. Load a recordable disc (blank disc).
[ AMS ]
2. Turn the ≠
(C31).
[YES]
3. Press the button to display "CREC MID".
4. When recording starts, light up "
@@@@" (@@@@ is the address).
5. About 1 minute later, press the
continuous recording.
[ AMS ]
6. Turn the ≠
MODE" (C30).
[YES]
7. Press the button to display "CPLAY MID".
8. "C = AD =
9. Check that the C1 error becomes below 80 and the AD error
below 2.
[MENU/NO]
10. Press the
[EJECT ]
§
button and take out the disc.
– 25 –
± knob to display "CPLAY MODE"
button when "C = AD =
±
knob to display "FBIAS CHECK"
/ c = ".
/ b =
/ a = ".
[EJECT ]
button, then press the
± knob to display "CPLAY MODE"
AD = ".
button to stop playback, then press the
±
knob to display "CPLAY MODE"
AD = ".
button to stop playback, then press the
± knob to display "CREC MODE"
REC
" and display "CREC
[MENU/NO]
button to stop
±
knob to display "CPLAY
" will be displayed.
button to stop playback, then press the
" is
".
§ but-