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MDS-JE780
5-5. 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.
2. Rotate the l AMS L knob and display "CREC1 MODE"
(C35).
3. Press the YES button again to display "CREC1 MID".
4. Press the LEVEL/DISPLAY/CHAR button.
Display "CREC (0300)" and start to recording.
5. Complete recording within 5 minutes.
6. Press the MENU/NO button and stop recording .
7. Press the AEJECT 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.
5-6. 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 8).
5-6-1. Temperature Compensation Offset Check
When performing adjustments, set the internal temperature and room
temperature to 22 to 28ºC.
Checks cannot be performed properly if performed after some time
from power ON due to the rise in the temperature of the IC and
diode, etc. So, perform the checks again after waiting some time.
Checking Procedure:
1. Rotate the l AMS L knob to display "TEMP CHECK".
(C12)
2. Press the YES 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.)
5-6-2. Laser Power Check
Before checking, check the Iop value of the optical pick-up.
(Refer to 5-8. Recording and Displaying Iop Information.)
Connection :
Optical pick-up
objective lens
BD board
CN105 pin 1 (I+3V)
CN105 pin 2 (Iop)
26
Checking Procedure:
1. Set the laser power meter on the objective lens of the optical
2. Then, rotate the l AMS L knob and display "LDPWR
3. Press the YES button once and display "L 0.93 mW $
4. Press the YES button once more and display " L 7.25 mW $
Specified Value :
Laser power meter reading : L 0.93mW: 0.85-0.91mW (260B)
Digital voltmeter reading : Optical pick-up displayed value ± 10%
5. Press the MENU/NO button and display "LDPWR CHECK"
Note 1: After step 4, each time the YES button is pressed, the
5-6-3. 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
Laser power
Procedure
meter
1. Rotate the l AMS L knob to display "Iop Compare".
2. Press the YES button and start measurements.
3. When measurements complete, the display changes to
4. Press the MENU/NO button to end.
Digital volt meter
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).
CHECK".
Check that the reading of the laser power meter become the
specified value.
". Check that the reading the laser power meter and digital
volt meter satisfy the specified value.
L 7.25mW: 6.80-7.20mW (260B)
(Optical pick-up label)
KMS
260B
(For details of the method for checking
20101
this value, refer to "5-8. Recording and
Displaying Iop Information".)
H0576
R
Iop = 57.6 mA in this case
Iop (mA) = Digital voltmeter reading (mV)/1 ( Ω )
and stop the laser emission.
(The MENU/NO button is effective at all times to stop the laser
emission.)
display will be switched between "L 0.73 mW $
"L 6.40 mW $
", and "L Wp
needs to be performed here.
temperature.
Iop [STOP]
Iop [7.0mW]
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.
".
0.90-0.96mW (260E)
7.00-7.50mW (260E)
",
$
". Nothing
"±xx%yy".
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