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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 emission,

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

Terminal.  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. 

Summary of Contents for YH-820

Page 1: ...LAYER Basic Model YH 820 PORTABLE DIGITAL AUDIO PLAYER Confidential SERVICEManual CONTENTS 1 Product Specifications 2 Block Diagram 3 Wiring Diagram 4 Exploded Views and Parts List 5 Electrical Parts List 6 Schematic Diagrams ...

Page 2: ...ELECTRONICS Samsung Electronics Co Ltd DEC 2004 Printed in Korea Code no AH68 01427X ...

Page 3: ...rrent for Appliances and Underwriters Laboratories UL Publication UL1410 59 7 With the unit completely reassembled plug the AC line cord directly into a 120V AC outlet With the unit s AC switch first in the ON position and then OFF measure the current between a known earth ground metal water pipe etc and all exposed metal parts Examples Handle brackets metal cabinets screwheads and control shafts ...

Page 4: ...nplug the unit s AC power cord from the AC power source before attempting to a Remove or reinstall any component or assembly b Disconnect an electrical plug or connector c Connect a test component in parallel with an electrolytic capacitor 3 Some components are raised above the printed circuit board for safety An insulation tube or tape is sometimes used The internal wiring may be clamped to preve...

Page 5: ...ready to install it Most replacement ESDs are packaged with leads that are electrically shorted together by conductive foam aluminum foil or other conductive materials 8 Immediately before removing the protective material from the leads of a replacement ESD touch the protective material to the chassis or circuit assembly into which the device will be installed 9 Minimize body motions when handing ...

Page 6: ...d 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 As...

Page 7: ...Samsung Electronics 2 1 2 Block Diagram ...

Page 8: ...Samsung Electronics 3 1 3 Wiring Diagram ...

Page 9: ...Samsung Electronics 4 1 4 Exploded Views and Parts List ...

Page 10: ...7 2703 002714 INDUCTOR SMD 22UH 10 2016 L8 3301 001705 BEAD SMD 1005 TP 82OHM 164MHZ 137OH L9 3301 001477 BEAD SMD 60ohm 2 0x1 2x0 6mm 3000mA TP LD1 2703 001873 INDUCTOR SMD 4 7uH 20 6060 LD2 2703 002187 INDUCTOR SMD 4 7uH 20 6645 MIC1 3003 001087 MIC CONDENSOR 2V 500UA 44DB 2 2KOHM PS100 AH63 00844A CUSHION BOTTOM YH 820 EVA PS130 AH63 00845A CUSHION TOP YH 820 PSR Q15 0505 001426 FET SILICON IRL...

Page 11: ...Samsung Electronics 12 1 This Document can not be used without Samsung s authorization 6 Schematic Diagram 1 1 MAIN Circuit ...

Page 12: ...12 2 Samsung Electronics This Document can not be used without Samsung s authorization 1 2 MAIN Test Point Waveform ...

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