Sony HCD-VZ50MD, Руководство по обслуживанию, Страница: 46 / 132

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6-14. ERROR RATE CHECK
6-14-1. CD Error Rate Check
Checking Procedure :
1. Load a check disc (MD) TDYS-1.
2. Move the multi-stick and display “CPLAY1MODE” (C34).
3. Press the PUSH ENTER button twice and display “CPLAY1
MID”.
4. The display changes to “C1 = AD = ”.
5. Check that the C1 error rate is below 20.
6. Press the CLEAR button while REC IT is lit, stop playback,
press the MD
Z
button while REC IT is off, and remove the
test disc.
6-14-2. MO Error Rate Check
Checking Procedure :
1. Load a continuously recorded test disc (MDW-74/GA-1).
(Refer to “6-5. Using the Continuously Recorded Disc”.)
2. Move the multi-stick and display “CPLAY1MODE” (C34).
3. Press the PUSH ENTER button and display “CPLAY1MID”.
11. Move the multi-stick until the waveform of the oscilloscope
moves closer to the specified value.
In this adjustment, waveform varies at intervals of approx. 2%.
Adjust the waveform so that the specified value is satisfied as
much as possible.
(Traverse Waveform)
12. Press the PUSH ENTER button, and save the adjustment re-
sults in the non-volatile memory. (“EFB = SAVE” will be
displayed for a moment.)
Next “EF MO ADJUS” (C07) is displayed. The disc stops ro-
tating automatically.
13. Press the MD
Z
button while REC IT is off and remove the
disc.
14. Load the check disc (MD) TDYS-1.
15. Move the multi-stick and display “EF CD ADJUS” (C08).
16. Press the PUSH ENTER button and display “EFB =
CD”.
Servo is imposed automatically.
17. Move the multi-stick so that the waveform of the oscilloscope
moves closer to the specified value.
In this adjustment, waveform varies at intervals of approx. 2%.
Adjust the waveform so that the specified value is satisfied as
much as possible.
(Traverse Waveform)
18. Press the PUSH ENTER button, display “EFB = SAVE”
for a moment and save the adjustment results in the non-vola-
tile memory.
Next “EF CD ADJUS” (C08) will be displayed.
19. Press the MD Z button while REC IT is off and remove the
check disc (MD) TDYS-1.
Note 1 : MO reading data will be erased during if a recorded disc is
used in this adjustment.
Note 2 : If the traverse waveform is not clear, connect the oscillo-
scope as shown in the following figure so that it can be
seen more clearly.
6-13. FOCUS BIAS ADJUSTMENT
Adjusting Procedure :
1. Load a test disk (MDW-74/GA-1).
2. Move the multi-stick and display “CPLAY1MODE”(C34).
3. Press the PUSH ENTER button and display “CPLAY1MID”.
4. Press the CLEAR button while REC IT is lit when “C1 =
AD = ” is displayed.
5. Move the multi-stick and display “FBIAS ADJUS”(C09).
6. Press the PUSH ENTER button and display “
/ a = ”.
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. Move the multi-stick in the right direction and find the focus
bias value at which the C1 error rate becomes 220 (Refer to
Note 2).
8. Press the PUSH ENTER button and display “ / b = ”.
9. Move the multi-stick in the left direction and find the focus bias
value at which the C1 error rate becomes 220.
10. Press the PUSH ENTER button and display “ / c =
”.
11. Check that the C1 error rate is below 20 and ADER is 00. Then
press the PUSH ENTER button.
12. If the “( ” in “ - - ( ” is above 20, press the PUSH
ENTER button.
If below 20, press the CLEAR button while REC IT is lit and
repeat the adjustment from step 2.
13. Press the MD Z button while REC IT is off and remove the
test 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.
VC
A
B
Specification A = B
VC
A
B
Specification A = B
330 k
Ω
Oscilloscope
10pF
BD (MD) board
CN105 pin
4
(TE)
CN105 pin
6
(VC)
C1 error
220
b c a Focus bias value
(F. BIAS)