Sony HCD-MD1EX - System Service Manual page 27

6-6. LASER POWER ADJUSTMENT
Connection :
Optical pick-up
objective lens
BD (MD) board
TP (I+3V)
TP (IOP)
Adjusting Procedure:
1. Set the laser power meter on the objective lens of the optical pick-
up from the disc slot. (If it cannot be set properly, press the
=0 or )+ button to move the optical pick-up).
Connect the digital voltmeter to TP (I+3V) and TP (IOP) of
the BD (MD) board.
[VOLUME+/–]
2. Press the button to display "LDPWR ADJUST".
(Laser power: For adjustment)
3. Press the p (CD) button once to display "LD 0.9 mW $
[VOLUME+/–]
4. Press the
reads 0.86 to 0.92 mW. Set the range knob of the laser power
meter to 10 mW, press the p (CD) button, and save the ad-
justment results in the non-volatile memory. ("LD SAVE $
" is displayed momentarily.)
5. "LD 7.0 mW $ " is next displayed.
[VOLUME+/–]
6. Press the
reads 6.9 to 7.1 mW, press the p (CD) button, and save the
adjustment results in the non-volatile memory. ("LD SAVE $
" is displayed momentarily.)
Note: Do not emit 7.0 mW continuously for more than 15 seconds.
[VOLUME+/–]
7. Press the button to display "LDPWR CHECK".
8. Press the p (CD) button once to display "LD 0.9 mW $
Check that the laser power meter reading is 0.85 to 0.91 mW.
9. Press the p (CD) button another time to diaplay "LD 7.0
mW $ ".
Check that the readings of the laser power meter and digital
voltmeter become the specified value.
Specified Value :
Laser power meter reading : 7.0 ± 0.1 mW
Digital voltmeter reading : Value displayed on optical pick-up la-
bel ± 10%
(Optical pick-up label)
KMS 260A
27X40
B0825
Iop = 82.5 mA in this case
Iop (mA) = Digital voltmeter reading (mV)/1 ( )
10. Press the ^ (CD) button to display "LDPWR CHECK" and
stop the laser emission.
(The ^ (CD) button is effective at all times to stop the laser
emission.)
Laser power
meter
Digital volt meter
button so that the laser power meter
button so that the laser power meter
6-7. TRAVERSE ADJUSTMENT
Connection :
BD (MD) board
TP69 (TEO)
TP1003 (VC)
Adjusting Procedure:
1. Connect an oscilloscope to TP69 (TEO) and TP1003 (VC) of
the BD (MD) board.
2. Load a recordable disc (any available on the market). (Refer
to Note 1.)
3. Press the =0 or )+ button to move the optical
pick-up outside the pit.
[VOLUME+/–]
4. Press the
5. Press the p (CD) button to display "EFB =
(Laser power READ power/Focus servo ON/tracking servo
OFF/spindle (S) servo ON)
[VOLUME+/–]
6. Press the
form becomes the specified value. (Press the
button changes the "EFB=
waveform changes by about 2% everytime when adjusted.
".
Adjust as close as possible to the specified value.
(Read power traverse adjustment)
(Traverse Waveform)
VC
Specified value : A = B
".
7. Press the p (CD) button and save the adjustment results in
the non-volatile memory (displayed as "EFB =
momentarliy and then displayed as "EFB =
[VOLUME+/–]
8. Press the
form becomes the specified value.
[VOLUME+/–]
(Pressing the
value and the waveform.) The waveform changes by about 2%
everytime when adjusted. Adjust as close as possible to the
specified value.
(Write Power Traverse Adjustment)
(Traverse Waveform)
VC
Specified value : A = B
9. Press the p (CD) button to save the adjustment results in the
non-volatile memory (displayed as "EFB =
momentarliy).
– 27 –
Oscilloscope
V: 0.5 v/div H: 10 ms/div
Input: DC mode
button to display "EFBAL ADJUST".
MO-R".
button so that the oscilloscope wave-
[VOLUME+/–]
" value and the waveform.) The
MO-W").
button so that the oscilloscope wave-
button changes the "EFB=
A
B
SAVE"
"
A
B
SAVE"