25
MDS-JB980
5-2. 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.
5-3. PRECAUTIONS FOR USE OF OPTICAL PICK-
UP (KMS-260B/260E)
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. Before connect-
ing the connector, be careful not to remove the solder. Also take
adequate measures to prevent damage by static electricity. Handle
the flexible board with care as it breaks easily.
Optical pick-up flexible board
5-4. PRECAUTIONS FOR ADJUSTMENTS
1) When replacing the following parts, perform the adjustments
and checks with
in the order shown in the following table.
2) Set the test mode when performing adjustments.
After completing the adjustments, exit the test mode.
Perform the adjustments and checks in “group S” of the test mode.
3) Perform the adjustments to be needed in the order shown.
4) Use the following tools and measuring devices.
• Check Disc (MD) TDYS-1
(Parts No. 4-963-646-01)
• Test Disk (MDW-74/GA-1) (Parts No. 4-229-747-01)
• Laser power meter LPM-8001 (Parts No. J-2501-046-A)
or
MD Laser power meter 8010S (Parts No. J-2501-145-A)
• Oscilloscope (Measure after performing CAL of prove.)
• Digital voltmeter
• Thermometer
• Jig for checking BD board waveform
(Parts No. : J-2501-196-A)
pick-up
flexible board
laser tap
5) When observing several signals on the oscilloscope, etc.,
make sure that VC and ground do not connect inside the oscillo-
scope.
(VC and ground will become short-circuited.)
6) Using the above jig enables the waveform to be checked with-
out the need to solder.
(Refer to Servicing Note on page 6.)
7) As the disc used will affect the adjustment results, make sure
that no dusts nor fingerprints are attached to it.
5-7. Initial setting of adjustment values
5-8. Recording of Iop information
5-9. TEMP ADJUST
5-10. Laser power adjustment
5-11. Iop NV Save
5-12. Traverse adjustment
5-13. Focus bias adjustment
5-16. Auto gain adjustment
5-6-4. AUTO CHECK
Optical
Pick-up
IC101
IC701
IC201
IC933
IC195
*
D101
IC803
Parts to be replaced
Adjustment
* The IC195 cannot be replaced with a new part.
For derail refer to “NOTES ON REPLACING BD BOARD OR MD MECHANISM DECK” (See page 8).