Sony PMC-MD55 Service Manual page 134

9. EF 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 oscilloscope
as shown in the following figure so that it can be seen more
clearly.
BD board
CN110 pin 3 (TEO)
CN110 pin 1 (VC)
Connection :
BD board
CN110 pin 3 (TEO)
CN110 pin 1 (VC)
Adjusting Procedure :
1. Connect an oscilloscope to CN110 pin 3 (TEO) and CN110
pin 1 (VC) on the BD board.
2. Load a disc (any available on the market). (Refer to Note 1)
[ ]
3. Press the M button to move the optical pick-up outside the
pit.
4. Turn the JOG dial to display "EFBAL ADJUST".
[YES, ENTER]
5. Press the
R".
(Laser power READ power/Focus servo ON/tracking servo
OFF/spindle (S) servo ON)
6. Turn the JOG dial so that the waveform of the oscilloscope
becomes the specified value.
(When the JOG dial is turned, the
and the waveform changes) In this adjustment, waveform var-
ies at intervals of approx. 2%. Adjust the waveform so that
the specified value is satisfied as much as possible.
(Read power traverse adjustment)
Traverse Waveform
VC
Specification A = B
[YES, ENTER]
7. Press the
ment to the non-volatile memory. ("EFB =
displayed for a moment. Then "EFB =
displayed)
oscilloscope
(DC range)
330 k Ω
+
–
10 pF
oscilloscope
(DC range)
+
V: 0.1 V/div
–
H: 10 ms/div
button to display "EFB =
of "EFB= " changes
A
B
button and save the result of adjust-
SAVE" will be
MO-W" will be
8. Turn the JOG dial so that the waveform of the oscilloscope
becomes the specified value.
(When the JOG dial is turned, the
and the waveform changes) In this adjustment, waveform var-
ies at intervals of approx. 2%. Adjust the waveform so that the
specified value is satisfied as much as possible.
(Write power traverse adjustment)
Traverse Waveform
VC
Specification A = B
[YES, ENTER]
9. Press the
sults in the non-volatile memory. ("EFB =
displayed for a moment)
10. "EFB = MO-P" will be displayed.
The optical pick-up moves to the pit area automatically and
servo is imposed.
11. Turn the JOG dial 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.
MO-
Traverse Waveform
VC
Specification A = B
[YES, ENTER]
12. Press the
sults in the non-volatile memory. ("EFB =
displayed for a moment)
Next "EFBAL ADJUST" is displayed. The disc stops rotating
automatically.
[MD EJECT
13. Press the
14. Load the check disc (MD) TDYS-1.
[YES, ENTER]
15. Press the
Servo is imposed automatically.
16. Turn the JOG dial 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
VC
Specification A = B
– 25 –
of "EFB- " changes
A
B
button, and save the adjustment re-
SAVE" will be
A
B
button, and save the adjustment re-
SAVE" will be
]
button and take out the disc.
Z
button to display "EFB =
A
B
CD".