Samsung YP-T55, Service Manual

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Samsung Electronics 1-4
1-4 Special Precautions and Warning Labels for Laser Products (Continued)
1-4-1 Warnings
1. When servicing, do not approach the
LASER exit with the eye too closely. In
case it is
necessary to confirm LASER beam emis-
sion, be sure to observe from a distance of
more than 30 cm from the surface of the
objective lens on the optical pick-up block.
2. Do not attempt to handle the objective lens
when the DISC is not on the tray.
1-4-2 Laser Diode Specifications
Material: GaAs+ GaAlAs
Wavelength: 760-800 nm
Emission Duration: Continuous
Laser Output: 0.2 mw (measured at a
1.6 mm distance from the objective lens
surface on the optical pick-up block.)
1-4-3 Handling the Optical Pick-up
1. Static electricity from clothing or the body
may cause electrostatic breakdown of the
laser diode in the Optical Pickup. Follow
this procedure:
2. Place a conductive sheet on the work bench
(i.e., the black sheet used for wrapping
repair parts.) Note: The surface of the work
bench should be covered by a copper
ground plane, which is grounded.
3. The repair technician must wear a wrist
strap which is grounded to the copper
sheet.
4. To remove the Optical Pickup block:
Place the set on the conductive sheet, and
momentarily touch the conductive sheet
with both hands. (While working, do not
allow any electrostatic sources--such as
clothes--to touch the unit.)
5. Ground the "Short Terminal" (located on the
PCB, inside the Pickup Assembly) before
replacing the Pickup. This terminal should
be shorted whenever the Pickup Assembly
is lifted or moved.
6. After replacing the Pickup, reopen the Short
See diagrams below:
Precautions
THE UNIT
(1) WRIST-STRAP
FOR GROUNDING
1M
1M
CONDUCTIVE SHEET
short
terminal
short terminal
short
terminal
short
terminal
SOH91VI(LDP)
SOH91CI(CAR,walkman)
SOH94T4N
(CMS-V10,CMS-V30)
SOH-A1
(CMS-V10,CMS-V30)
1-5 Special Precautions for HDD
* HDD Data Maintenance Step
1. Since the data on the HDD is weak to mechanical shock, place the HDD in a safe
location that is free from mechanical shock once it is removed from the main unit.
2. In order to safe keep the data on the HDD, back up the data before the repair or
make sure not to place the HDD near any electrical appliance that generates a
strong magnetic field.