Laser Power Adjustment - Sony MDS-JB920 Service Manual

7. INITIAL SETTING OF ADJUSTMENT VALUE
Note:
Mode which sets the adjustment results recorded in the non-volatile
memory to the initial setting value. However the results of the tempera-
ture compensation offset adjustment will not change to the initial setting
value.
If initial setting is performed, perform all adjustments again excluding the
temperature compensation offset adjustment.
For details of the initial setting, refer to "4. Precautions on Adjustments"
and execute the initial setting before the adjustment as required.
Setting Procedure :
[ AMS ]
1. Rotate the
≠ ±
(C24)".
[YES]
2. Press the button. "Complete!" will be displayed mo-
mentarily and initial setting will be executed, after which "ADJ
CLEAR" will be displayed.
8. RECORDING AND DISPLAYING THE IOP
INFORMATION
The IOP data can be recorded in the non-volatile memory. The
IOP value on the label of the optical pickup and the IOP value
after the adjustment will be recorded. Recording these data elimi-
nates the need to read the label on the optical pick-up.
Recording Procedure :
[ AMS ]
1. While pressing the ≠
connect the power plug to the outlet, and release the
[ AMS ]
knob and p button.
±
≠
[ AMS ]
2. Rotate the ≠ ±
[YES]
press the button.
[ AMS ]
≠ ±
3. Rotate the
[YES]
and press the button.
4. The display becomes Ref=@@@.@ (@ is an arbitrary num-
ber) and the numbers which can be changed will blink.
5. Input the IOP value written on the optical pick-up.
To select the number : Rotate the
To select the digit : Press the
[YES]
6. When the button is pressed, the display becomes
"Measu=@@@.@" (@ is an arbitrary number).
7. As the adjustment results are recorded for the 6 value. Leave
[YES]
it as it is and press the
8. "Complete!" will be displayed momentarily. The value will
be recorded in the non-volatile memory and the display will
become "Iop Write".
Display Procedure :
[ AMS ]
1. Rotate the ±
≠
2. "@@.@/##.#" is displayed and the recorded contents are dis-
played.
@@.@ indicates the Iop value labeled on the pick-up.
##.# indicates the Iop value after adjustment
[ AMS ]
3. To end, press the ≠
to display "Iop Read".
knob to display "ADJ CLEAR
[ ]
knob and p button,
±
[ ]
knob to display "[Service]", and
knob to display "Iop.Write" (C28),
[ AMS ]
± knob.
≠
[ AMS ]
≠ ± knob
button.
knob to display "Iop.Read"(C27).
[MENU/NO]
± button or button
9. TEMPERATURE COMPENSATION OFFSET
ADJUTMENT
Save the temperature data at that time in the non-volatile memory
as 25 ˚C reference data.
Note :
1. Usually, do not perform this adjustment.
2. Perform this adjustment in an ambient temperature of 22 ˚C to 28 ˚C.
Perform it immediately after the power is turned on when the internal
temperature of the unit is the same as the ambient temperature of 22 ˚C
to 28 ˚C.
3. When D101 has been replaced, perform this adjustment after the tem-
perature of this part has become the ambient temperature.
Adjusting Procedure :
[ AMS ]
1. Rotate the
≠
[YES]
2. Press the
3. "TEMP = [OK" and the current temperature data will be
displayed.
4. To save the data, press the
When not saving the data, press the
[YES]
5. When the
be displayed and turned back to "TEMP ADJUS" display then.
[MENU/NO]
When the
be displayed immediatelly.
Specified Value :
The "TEMP = " should be within "E0 - EF", "F0 - FF", "00 -
0F", "10 - 1F" and "20 - 2F".

10. LASER POWER ADJUSTMENT

Check the IOP value of the optical pick-up before adjustments.
(Refer to 5-8. Recording and Displaying IOP Information.)
Connection :
Optical pick-up
objective lens
BD board
CN110 pin 5 (I +3V)
CN110 pin 4 (IOP)
Adjusting Procedure :
1. Set the laser power meter on the objective lens of the optical
pick-up. (When it cannot be set properly, press the 0 button
[ ]
or ) button to move the optical pick-up.)
Connect the digital volt meter to CN110 pin 5 (I+3V) and
CN110 pin 4 (IOP).
[ AMS ]
2. Rotate the ≠
(C10).
(Laser power : For adjustment)
[YES]
3. Press the button once and display "LD 0.9 mW $
[ AMS ]
4. Rotate the
≠
laser power meter becomes 0.85 to 0.91 mW. Press the
button after setting the range knob of the laser power meter,
and save the adjustment results. ("LD SAVE $
displayed for a moment.)
5. Then "LD 7.0 mW $
[ AMS ]
6. Rotate the ≠
laser power meter becomes 6.9 to 7.1 mW, press the
button and save it.
Note: Do not perform the emission with 7.0 mW more than 15 seconds
continuously.
– 27 –
± knob and display "TEMP ADJUS".
button and select the "TEMP ADJUS" mode.
[YES]
button.
[MENU/NO]
button is pressed, "TEMP =
button is pressed, "TEMP ADJUS" will
laser
power meter
digital voltmeter
+
–
± knob and display "LDPWR ADJUS"
± knob so that the reading of the
" will be displayed.
±
knob so that the reading of the
button.
SAVE" will
[ ]
".
[YES]
" will be
[YES]