Sony HCD-MD1EX - System Service Manual page 28

10. Next "EFB = MO-P" is displaed, the optical pick-up moves
to the internal circumference of the pit and servo is imposed.
[VOLUME+/–]
11. Press the button so that the oscilloscope wave-
form becomes the specified value.
The waveform changes by about 2% everytime when adjusted.
Adjust as close as possible to the specified value.
(Traverse Waveform)
VC
Specified value : A = B
12. Press the p (CD) button and save the adjustment results in
the non-volatile memory (displayed as "EFB =
momentarliy).
"EFBAL: CD is next displayed and the disc stops rotating au-
tomatically.
13. Press the 6 (MD) button and remove the disc.
14. Load the check disc (MD) TDYS-1.
15. Press the p (CD) button to display "EFB =
servo is imposed automatically.
[VOLUME+/–]
16. Press the button so that the oscilloscope wave-
form becomes the specified value.
The waveform changes by about 2% everytime when adjusted.
Adjust as close as possible to the specified value.
(Traverse Waveform)
VC
Specified value : A = B
17. Press the p (CD) button and save the adjustment results in
the non-volatile memory after "EFB =
momentarliy displayed.
"EFBAL ADJUST" is next displayed.
18. Press the 6 (MD) button and remove the check disc (MD)
TDYS-1.
Note 1: The data will be overwritten on the MO and erased when a re-
corded disc is used in this adjustment.
Note 2: If the traverse waveform is not clear, connect the oscilloscope as
shown in the following figure so that it can be seen more clearly.
330 k
BD (MD) board
TP69 (TEO)
TP1003 (VC)
A
B
SAVE"
CD". The
A
B
SAVE" is
Oscilloscope
10 pF
6-8. FOCUS BIAS ADJUSTMENT
Adjusting Procedure :
1. Load a continuously recorded disc (Refer to 6-4. Creating the
Continuously Recorded Disc").
[VOLUME+/–]
2. Press the
3. Press the p (CD) button to display "CPLAY MID".
4. When "C =
button.
[VOLUME+/–]
5. Press the
6. Press the p (CD) button to display "
The first four digits indicate the C1 error rate, the two digits
after the "/" indicate ADER and the two digits after "a =" indi-
cate the focus bias value.
[VOLUME+/–]
7. Press the
value at which the C1 error rate becomes approximately about
200. (Refer to Note 2).
8. Press the p (CD) button to display "
[VOLUME+/–]
9. Press the
value at which the C1 error rate becomes about 200.
The C1 error rate at this time should be almost same as the
value set in step 7.
10. Press the p (CD) button to display "
11. Check that the C1 error rate is below 50 and that ADER is 00.
and press the p (CD) button.
12. If the value of "( )" in the "
above 20, press the p (CD) button.
If below, press the ^ (CD) button and start from step 2
again.
13. Press the 6 (MD) button and remove the continuously re-
corded disc.
Note 1: The following figure shows the relation between the C1 error
and focus bias value. Look for points a and b in the following
figure by the adjustment avove. The focus position (point c) is
automatically calculated from points a and b.
Note 2: As the C1 error rate changes, use the average value in the ad-
justment.
C1 error
about
200
b
– 28 –
button and display "CPLAY MODE".
" is displayed, press the ^ (CD)
AD =
button to display "FBIAS ADJUST".
/
button, and look for the focus bias
/
button, and look for the focus bias
/
- - ( )" displayed is
Focus bias value
(F. BIAS)
c a
a = ".
b = ".
c = ".