Focus Bias Adjustment; Error Rate Check; Focus Bias Check - Sony HCD-EX770 Service Manual

5-8. FOCUS BIAS ADJUSTMENT

Adjusting Method:
1. Load a continuously recorded disc (Refer to "5-4. Creating
MO Continuously Recorded Disc".).
2. Turning the SELECTOR knob and display "CPLAY MODE".
3. Press the ENTER/YES button and display "CPLAY MID".
4. Press the EDIT/NO button when "C1=
played.
5. Turning the SELECTOR knob and display "FBIAS AD-
JUST".
6. Press the ENTER/YES button and display "
The first four digits indicate the C1 error rate, the two digits
after [/] indicate ADER, and the 2 digits after [a=] indicate the
focus bias value.
7. Turning the SELECTOR knob in the clockwise direction and
find the focus bias value at which the C1 error rate becomes
220. (Refer to note 2.)
8. Press the ENTER/YES button and display "
9. Turning the SELECTOR knob in the counterclockwise
derection and find the focus bias value at which the C1 error
rate becomes 220. (Refer to note 2.)
10. Press the ENTER/YES button and display "
11. Check that the C1 error rate is below 50 and ADER is 00.
Then press the ENTER/YES button.
12. If the "( )" in " - -
ENTER/YES button.
If below 20, press the EDIT/NO button and repeat the ad-
justment from step 2 again.
13. Press the EDIT/NO button and press the § EJECT button
to remove the continuously recorded disc.
Note 1: The relation between the C1 error and focus bias is as
shown in the following figure. Find points a and b in the
following figure using the above adjustment. The focal
point position c is automatically calculated from points a
and b.
Note 2: As the C1 error rate changes, perform the adjustment us-
ing the average vale.
C1 error
220
b c
AD= " is dis-
/ a= ".
/ b= ".
/ c= ".
( )" is above 20, press the
Focus bias value
(F. BIAS)
a

5-9. ERROR RATE CHECK

5-9-1. CD Error Rate Check
Checking Method:
1. Load a test disc TDYS-1.
2. Turning the SELECTOR knob and display "CPLAY MODE".
3. Press the ENTER/YES button and display "CPLAY MID".
4. "C1= AD=
5. Check that the C1 error is below 20.
6. Press the EDIT/NO button, stop playback, press the
§ EJECT button, and remove the test disc.
5-9-2. MO Error Rate Check
Checking Method:
1. Load a continuously recorded disc (Refer to "5-4. Creating
MO Continuously Recorded Disc".).
2. Turning the SELECTOR knob and display "CPLAY MODE".
3. Press the ENTER/YES button and display "CPLAY MID".
4. "C1= AD= " is displayed.
5. If the C1 error is below 50, check that ADER is 00.
6. Press the EDIT/NO button, stop playback, press the
§ EJECT button, and remove the continuously recorded disc.

5-10. FOCUS BIAS CHECK

Change the focus bias and check the focus tolerance amount.
Checking Method:
1. Load a continuously recorded disc (Refer to "5-4. Creating
MO Continuously Recorded Disc".).
2. Turning the SELECTOR knob and display "CPLAY MODE".
3. Press the ENTER/YES button and display "CPLAY MID".
4. Press the EDIT/NO button when "C1=
played.
5. Turning the SELECTOR knob and display "FBIAS CHECK".
6. Press the ENTER/YES 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 00.
7. Press the ENTER/YES button and display "
Check that the C1 error is not below 220 and ADER is not
above 00 every time.
8. Press the ENTER/YES button and display "
Check that the C1 error is not below 220 and ADER is not
above 00 every time.
9. Press the EDIT/NO button, next press the § EJECT button,
and remove the continuously recorded disc.
Note 1: If the C1 error and ADER are above 00 at points a or b,
the focus bias adjustment may not have been carried out
properly. Adjust perform the beginning again.
– 30 –
" is displayed.
AD= " is dis-
/ c= ".
/ b= ".
/ a= ".