Sony MDS-EX77, Service Manual

Page: 29 / 73

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5-7. TRAVERSE (E-F BALANCE) ADJUSTMENT
Note 1: Data will be erased during MO reading if a recorded
disc is used in this adjustment.
Note 2: If the traverse waveform is not clear, connect the os-
cilloscope as shown in the following figure so that it
can be seen more clearly.
Connection:
8. Turning the SELECTOR knob so that the waveforms of the
oscilloscope becomes the specified value. (When the
SELECTOR knob is turned, the “
” of “EFB= MO-W”
changes and the waveform changes.)
In this adjustment, waveform varies at intervals of approx.
2%. Adjust the waveform so that the specified value is satis-
fied as much as possible.
(MO write power traverse adjustment)
+
–
oscilloscope
(DC range)
10 pF
330 k
Ω
CN110 pin
3
(TEO)
CN110 pin
2
(VC)
BD board
+
–
BD board
CN110 pin
3
(TEO)
CN110 pin
2
(VC)
oscilloscope
(DC range)
V: 0.1 V/div
H: 10 ms/div
A
B
VC
specification: A=B
(Traverse Waveform)
9. Press the ENTER/YES button, and save the result of adjust-
ment to the non-volatile memory.
(“EFB=
SAVE” will be displayed for a moment. Then
“EFB= MO-P” will be displayed.)
10. The optical pick-up moves to the pit area automatically and
servo is imposed.
11. Turning the SELECTOR knob until the waveforms 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.
1. Connect an oscilloscope to CN110 pin
3
(TEO) and CN110
pin
2
(VC) of the BD board.
2. Load a MO disc (any available on the market). (Refer to note
1.)
3. Press the
0
button or
)
button and move the optical
pick-up outside the pit.
4. Turning the SELECTOR knob and display “EFBAL AD-
JUST”.
5. Press the ENTER/YES button and display “EFB=
MO-R”.
(Laser power READ power/focus servo ON/tracking servo
OFF/spindle (S) servo ON)
6. Turning the SELECTOR knob so that the waveforms of the
oscilloscope becomes the specified value. (When
the SELECTOR knob is turned, the “
” of “EFB=
MO-
R” changes and the waveform changes.)
In this adjustment, waveform varies at intervals of approx. 2%.
Adjust the waveform so that the specified value is satisfied as
much as possible.
(MO read power traverse adjustment)
(Traverse Waveform)
A
B
VC
specification: A=B
Adjusting Method:
(Traverse Waveform)
A
B
VC
specification: A=B
12. Press the ENTER/YES button, and save the result of adjust-
ment to the non-volatile memory.
(“EFB=
SAVE” will be displayed for a moment. Then
“EFBAL CD” will be displayed.)
The disc stops rotating automatically.
13. Press the § EJECT button and remove the MO disc.
14. Load the test disc TDYS-1.
15. Press the ENTER/YES button and display “EFB=
CD”.
Servo is imposed automatically.
16. Turning the SELECTOR knob until the waveforms 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.
17. Press the ENTER/YES button, and save the result of adjust-
ment to the non-volatile memory.
(“EFB=
SAVE” will be displayed for a moment. Then
“EFBAL ADJUST” will be displayed.)
18. Press the
§
EJECT button and remove the test disc TDYS-1.
(Traverse Waveform)
A
B
VC
specification: A=B
7. Press the ENTER/YES button, and save the result of adjust-
ment to the non-volatile memory.
(“EFB=
SAVE” will be displayed for a moment. Then
“EFB= MO-W” will be displayed.)