Sony MXD-D4 Service Manual page 35

5. USING THE CONTINUOUSLY RECORDED DISC
* This disc is used in focus bias adjustment and error rate check.
The following describes how to create a continuous recording
disc.
1. Insert a disc (blank disc) commercially available.
[ AMS
2. Rotate the l L
"CREC 2MODE" (C37).
[YES]
3. Press the button again to display "CREC 2MID".
Display "CREC (0300)" and start to recording.
4. Complete recording within 5 minutes.
[MENU/NO]
5. Press the button and stop recording .
[ EJECT]
A
6. Press the button and remove the disc.
The above has been how to create a continuous recorded data for
the focus bias adjustment and error rate check.
Note: Be careful not to apply vibration during continuous recording.
6. CHECKS PRIOR TO REPAIRS
These checks are performed before replacing parts according to
"approximate specifications" to determine the faulty locations. For
details, refer to "Checks Prior to Parts Replacement and Adjust-
ments" (see page 9).
6-1. Temperature Compensation Offset Check
When performing adjustments, set the internal temperature and
room temperature to 22 to 28ºC.
Checking Procedure:
[ AMS
1. Rotate the l L
CHECK" (C12).
[YES]
2. Press the button.
3. "T=@@(##) [OK" should be displayed. If "T=@@ (##) [NG"
is displayed, it means that the results are bad.
(@@ indicates the current value set, and ## indicates the value
written in the non-volatile memory.)
6-2. Laser Power Check
Before checking, check the Iop value of the optical pick-up.
(Refer to 8. Recording and Displaying the Iop Information (see
page 38.)
Connection:
Optical pick-up
objective lens
BD (MD) board
CN105 pin 1 (I +3 V)
CN105 pin 2 (IOP)
]
(MD) knob and display
]
(MD) knob to display "TEMP
laser
power meter
digital voltmeter
+
–
Checking Procedure:
1. Set the laser power meter on the objective lens of the optical
pick-up. (When it cannot be set properly, press the m button
or M button to move the optical pick-up.)
Connect the digital volt meter to CN105 pin 1 (I+3V) and
CN105 pin 2 (IOP).
[ AMS
2. Then, rotate the l
"LDPWR CHECK" (C13).
[YES]
3. Press the button
once and display "LD 0.9 mW $
laser power meter become 0.84 to 0.92 mW.
[YES]
4. Press the button once more and display " LD 8.4 mW $
". Check that the reading the laser power meter and digital
volt meter satisfy the specified value.
Specified Value:
Laser power meter reading : 8.4 ± 0.3 mW
Digital voltmeter reading : Optical pick-up displayed value ± 10%
(Optical pick-up label)
(For details of the method for
KMS 262A
checking this value, refer to "8.
20101
Recording and Displaying the Iop
B0825
Information".)
Iop = 82.5 mA in this case
Iop (mA) = Digital voltmeter reading (mV)/1 ( Ω )
[MENU/NO]
5. Press the button and display "LDPWR CHECK"
(C13) and stop the laser emission.
[MENU/NO]
(The button is effective at all times to stop the laser
emission.)
Note: After step 4, each time the
will be switched between "LD 0.7 mW $
and "LD Wp $
Check Location: BD (MD) board (see page 42)
6-3. Iop Compare
The current Iop value at laser power 7 mW output and reference
Iop value (set at shipment) written in the nonvolatile memory are
compared, and the rate of increase/decrease will be displayed in
percentage.
Note: Perform this function with the optical pick-up set at room
temperature.
Procedure:
[ AMS ]
1. Rotate the
l L
(C27).
[YES]
2. Press the button and start measurements.
3. When measurements complete, the display changes to
"±xx%yy".
xx is the percentage of increase/decrease, and OK or NG is
displayed at yy to indicate whether the percentage of increase/
decrease is within the allowable range.
4. Press the ? / button to display " <MD Test> 5", and press the
1
[MENU/NO]
button to end.
]
L (MD) knob and display
". Check that the reading of the
[YES]
button is pressed, the display
", "LD 6.2 mW $
". Nothing needs to be performed here.
(MD) knob to display "Iop Compare"
",
35