Electrical Adjustments; Precautions For Checking Laser Diode Emission; Precautions For Use Of Optical Pick-Up (Kms-260A); Precautions For Adjustments - Sony HCD-EX770 Service Manual

5-1. PRECAUTIONS FOR CHECKING LASER DI-
ODE EMISSION
To check the emission of the laser diode during adjustments, never
view directly from the top as this may lose your eyesight.
5-2. PRECAUTIONS FOR USE OF OPTICAL
PICK-UP (KMS-260A)
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 con-
necting the connector, be careful not to remove the solder. Also
tale adequate measures to prevent damage by static electricity.
Handle the flexible board with care as it breaks easily.
Pick-up
Optical pick-up flexible board
SECTION 5

ELECTRICAL ADJUSTMENTS

Flexible board
Laser tap

5-3. PRECAUTIONS FOR ADJUSTMENTS

1) When replacing the following parts, perform the adjustments
and checks with ® in the order shown in the following table.
Optical
Pick-up IC171 D101
1. Temperature
compensation
offset adjustment
2. Laser power
adjustment
3. Traverse
adjustment
4. Focus bias
adjustment
5. Error rate check
2) Set the test mode when performing adjustments.
After completing the adjustments, exit the test mode.
3) Perform the adjustments in the order shown.
4) Use the following tools and measuring devices.
• Check Disc (MD) TDYS-1
(Parts No. 4-963-646-01)
• Laser power meter LPM-8001
(Parts No. J-2501-046-A)
• Oscilloscope (Measure after preforming CAL of prove.)
• Digital voltmeter
• Thermometer
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)
5-4. CREATING MO CONTINUOUSLY RECORDED
DISC
* This disc is used in focus bias adjustment and error rate check.
The following describes how to create a MO continuous record-
ing disc.
1. Set the test mode.
2. Insert a MO disc (blank disc) commercially available.
3. Turning the SELECTOR knob and display "CREC MODE".
4. Press the ENTER/YES button and display "CREC MID".
"CREC (0300)" is displayed for a moment and recording starts.
5. Complete recording within 5 minutes.
6. Press the EDIT/NO button and stop recording.
7. Press the § EJECT button and remove the MO disc.
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.
– 27 –
Table 5-1.
BD board
IC101, IC121, IC192
×
® ®
×
® ®
×
® ®
×
® ®
×
® ®
®
®
®
®
®