Sony MDS-JA20ES Service Manual page 29

[YES]
9. Press the button 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 rotate the
knob.
(Traverse Waveform)
VC
Specified value : Below 10% offset value
Offset value (%) =
[YES]
11. Press the button display "EF MO CHECK"
The disc stops rotating automatically.
12. Press the § button and remove the disc.
13. Load the check disc (MD) TDYS-1.
[ AMS ]
±
14. Roteto the ≠
(C04).
[YES]
15. Press the button and display "EFB =
imposed automatically.
16. Observe the waveform of the oscilloscope, and check that the
specified value is satisfied. Do not rotate the
knob.
(Traverse Waveform)
VC
Specified value : Below 10% offset value
Offset value (%) =
[YES]
17. Press the button and display "EF CD CHECK".
18. Press the § button and remove the check disc (MD) TDYS-1.
MO-P".
[ AMS ]
≠
A
B
I A – B I
X 100
2 (A + B)
knob and display "EF CD CHECK"
CD". Servo is
[ AMS ]
≠
A
B
I A – B I
X 100
2 (A + B)
5-6-4. Focus Bias Check
Change the focus bias and check the focus tolerance amount.
Checking Procedure :
1. Load a test disk (MDW-74/AU-1).
± A disc is loaded automatically, if pushing the tray.
[ AMS ]
2. Rotate the ≠
(C30).
[YES]
3. Press the
[MENU/NO]
4. Press the
displayed.
[ AMS ]
5. Rotate the
≠
(C05).
[YES]
6. Press the
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.
[YES]
7. Press the
Check that the C1 error is below 220 and ADER is below 2.
[YES]
8. Press the
Check that the C1 error is below 220 and ADER is below 2.
[MENU/NO]
9. Press the
remove the test disc.
5-6-5. C PLAY Check
±
MO Error Rate Check
Checking Procedure :
1. Load a test disk (MDW-74/AU-1).
A disc is loaded automatically, if pushing the tray.
[ AMS ]
2. Rotate the ≠
(C30).
[YES]
3. Press the
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
the § button, and test disc.
CD Error Rate Check
Checking Procedure :
1. Load a check disc (MD) TDYS-1.
A disc is loaded automatically, if pushing the tray.
[ AMS ]
2. Rotate the ≠
(C30).
[YES]
3. Press the
4. The display changes to "C =
5. Check that the C1 error rate is below 50.
[MENU/NO]
6. Press the
the § button, and the test disc.
5-6-6. 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.
A disc is loaded automatically, if pushing the tray.
[ AMS ]
2. Rotate the ≠
(C31).
[YES]
3. Press the
4. When recording starts, "
"CREC @@@@" (@@@@ is the address), and recording
starts.
5. About 1 minute later, press the
continuous recording.
[ AMS ]
6. Rotate the
MODE"(C30).
[YES]
7. Press the
– 29 –
±
knob and display "CPLAY MODE"
button twice and display "CPLAY MID".
button when "C =
± knob and display "FBIAS CHECK"
button and display " /
button and display " /
button and display " /
button, next press the § button, and
± knob and display "CPLAY MODE"
button and display "CPLAY MID".
AD =
button, stop playback, press
± knob and display "CPLAY MODE"
button twice and display "CPLAY MID".
AD =
button, stop playback, press
± knob to display "CREC MODE"
button to display the "CREC MID".
REC " is displayed, this becomes
[MENU/NO]
± knob to display "C PLAY
≠
button to display "C PLAY MID".
AD = " is
c = ".
b = ".
a = ".
".
".
button to stop