Electrical Adjustments - Sony MDS-DRE1 Service Manual

Precautions for Checking Laser Diode Emission
To check the emission of the laser diode during adjustments, never
view directly from the top as this may lose your eye-sight.
Precautions for Use of optical pick-up (KMS-210A)
As the laser diode in the optical pick-up is easily damaged by
static electricity, solder the laser tap of the flexible board when
using it.Before disconnecting the connector, desolder first. Be-
fore connecting the connector, be careful not to remove the solder.
Also take adequate measures to prevent damage by static electric-
ity. Handle the flexible board with care as it breaks easily.
Optical pick-up flexible board
• Abbreviation
MO: Recordable disc
CD: Disc for playback only
SECTION 5

ELECTRICAL ADJUSTMENTS

Precautions for Adjustments
1) When replacing the following parts, perform the adjustments
2. Laser power
2) Set the test mode when performing adjustments.
3) Perform the adjustments in the order shown.
laser tap
4) Use the following tools and measuring devices.
5) When observing several signals on the oscilloscope, etc.,
Laser power meter
When performing laser power checks and adjustment (electrical
adjustment), use of the new MD laser power meter 8010S (J-2501-
145-A) instead of the conventional laser power meter is conve-
nient.
It sharply reduces the time and trouble to set the laser power meter
sensor onto the objective lens of the pick-up.
Creating Continuously Recorded Disc
* This disc is used in focus bias adjustment and error rate check.
1. Insert a MO disc (blank disc) commercially available.
2. Rotate the
3. Press the
4. Press the
5. Complete recording within 5 minutes.
6. Press the
7. Press the
The above has been how to create a continuous recording data for
the focus bias adjustment and error rate check.
Note:
• Be careful not to apply vibration during continuous recording.
– 15 –
and checks with ® in the order shown in the following table.
Optical
Pick-up
IC171
1. Temperature
compensation
G
offset adjustment
¬
adjustment
3. Traverse
¬
adjustment
4. Focus bias
¬
adjustment
5. Error rate check
¬
After completing the adjustments, exit the test mode.
• Check Disc (MD) TDYS-1
• Laser power meter LPM-8001 (Parts No. J-2501-046-A) or
MD Laser power meter 8010S (Parts No. J-2501-145-A)
• Oscilloscope
• Digital voltmeter
• Thermometer
make sure that VC and ground do not connect inside the oscil-
loscope.
(VC and ground will become short-circuited.)
The following describes how to create a continuous recording
disc.
[AMS]
knob and display "CREC MODE".
[ENTER/YES]
button and display "CREC IN".
[ENTER/YES]
button again to display "CREC MID".
"CREC (0300" is displayed for a moment and recording starts.
[EDIT/NO]
button and stop recording .
[ EJECT]
§ button and remove the MO disc.
BD Board
D101 IC101, IC121, IC191
¬ ¬ ¬
¬
G G
¬
¬ G
¬ G ¬
¬ G ¬
(Parts No. 4-963-646-01)