Sony MDS-JB920 Service Manual page 30

13. ERROR RATE CHECK
13-1. CD Error Rate Check
Checking Procedure :
1. Load a check disc (MD) TDYS-1.
[ AMS ]
±
2. Rotate the ≠
(C30).
[YES]
3. Press the button twice and display "CPLAY MID".
4. The display changes to "C =
5. Check that the C1 error rate is below 20.
[MENU/NO]
6. Press the
[ EJECT]
§ button, and remove the test disc.
13-2. MO Error Rate Check
Checking Procedure :
1. Load a test disc (MDW-74/AU-1).
[ AMS ]
±
2. Rotate the ≠
(C30).
[YES]
3. Press the button and display "CPLAY MID".
4. The display changes to "C1 =
5. If the C1 error rate is below 50, check that ADER is 00.
[MENU/NO]
6. Press the
[ EJECT]
§
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).
[ AMS ]
≠ ±
2. Rotate the
(C30).
[YES]
3. Press the button twice and display "CPLAY MID".
[MENU/NO]
4. Press the button when "C =
displayed.
[ AMS ]
5. Rotate the ≠ ±
(C05).
[YES]
6. Press the button and 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 and display "
Check that the C1 error is below 220 and ADER is below 2.
[YES]
8. Press the button and display "
Check that the C1 error is below 220 and ADER is below 2
[MENU/NO]
9. Press the button, next press the
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.
knob and display "CPLAY MODE"
AD = ".
button, stop playback, press the
knob and display "CPLAY MODE"
AD = ".
button, stop playback, press the
knob and display "CPLAY MODE"
AD =
knob and display "FBIAS CHECK"
/ c = ".
/ b = ".
/ a = ".
[ EJECT]
§
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.
[ AMS ]
2. Rotate the ≠
(C26).
[YES]
3. When the
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)".
[ EJECT]
4. Press the §
15-2. MO Auto Gain Control Output Level Adjustment
Adjusting Procedure :
1. Insert the reference disc (MDW-74/AU-1) for recording.
[ AMS ]
2. Rotate the ≠
(C25).
[YES]
3. When the
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)".
[ EJECT]
4. Press the §
" is
but-
– 30 –
± knob to display "AG Set (CD)"
button is pressed, the adjustment will be per-
button to remove the disc.
± knob to display "AG Set (MO)"
button is pressed, the adjustment will be per-
button to remove the disc.