Sony PMC-MD55 Service Manual page 24

7. TEMPERATURE COMPENSATION OFFSET
ADJUSTMENT
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 :
1. Turn the JOG dial to display "TEMP ADJUST".
[YES, ENTER]
2. Press the
JUST" mode.
3. "TEMP = " and the current temperature data will be dis-
played.
4. To save the data, press the
When not saving the data, press the
[YES, ENTER]
5. When the button is pressed, "TEMP =
will be displayed and turned back to "TEMP ADJUST" dis-
[NO, CANCEL]
play then. When the
ADJUST" will be displayed immediately.
Specified Value :
The "TEMP = " should be within "E0 - EF", "F0 - FF", "00 -
0F", "10 - 1F" and "20 - 2F".
8. LASER POWER ADJUSTMENT
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 voltmeter to CN110 pin 5 (I+3V) and
CN110 pin 4 (IOP) on the BD board.
2. Turn the JOG dial to display "LDPWR ADJUST".
(Laser power : For adjustment)
[YES, ENTER]
3. Press the
$ ".
4. Turn the JOG dial so that the reading of the laser power meter
becomes 0.85 to 0.91 mW. Press the
after setting the range knob of the laser power meter, and save
the adjustment results. ("LD SAVE $
a moment)
5. Then "LD 7.0 mW $ " will be displayed.
6. Turn the JOG dial so that the reading of the laser power meter
becomes 6.9 to 7.1 mW, press the
save it.
Note: Do not perform the emission with 7.0 mW more than 15 seconds
continuously.
button to select the "TEMP AD-
[YES, ENTER]
button.
[NO, CANCEL]
button.
SAVE"
button is pressed, "TEMP
laser
power meter
digital voltmeter
+
–
[ ]
button once to display "LD 0.9 mW
[YES, ENTER]
" will be displayed for
[YES, ENTER]
button to
7. Then, turn the JOG dial to display "LDPWR CHECK".
[YES, ENTER]
8. Press the
$ ". Check that the reading of the laser power meter become
0.85 to 0.91 mW.
[YES, ENTER]
9. Press the
7.0 mW $
and digital voltmeter satisfy the specified value.
Note down the digital voltmeter reading value.
Specified Value:
Laser power meter reading: 7.0 ± 0.2 mW
Digital voltmeter reading : Value on the optical pick-up label
(Optical pick-up label)
KMS260A
27X40
B0825
lOP=82.5 mA in this case
lOP (mA) = Digital voltmeter reading (mV)/1 ( Ω )
[NO, CANCEL]
10. Press the
and stop the laser emission.
[NO, CANCEL]
(The
the laser emission)
Note 1: After step 9, each time the
display will be switched "LD 0.7 mW $
and "LD WP
here.
button
– 24 –
button once to display "LD 0.9 mW
button once more to display "LD
". Check that the reading the laser power meter
±10%
button to display "LDPWR CHECK"
button is effective at all times to stop
[YES, ENTER]
$ ". Nothing needs to be performed
button is pressed, the
", "LD 6.2 mW $ ",