Samsung SN-S082D Service Manual - Page 3

1. Safety Precautions 1-1. Safety Precautions for Repairs 1) Since the equipment uses laser diode, ensure that eyes and parts of the body do not come near the laser diode while performing repair service. 2) Do not disassemble pickup to repair. If the laser diode is faulty, then replace the complete pickup assembly. 3) Perform repair services away from electrical equipments such as TV to avoid interference from these equipments. 4) Ensure to unplug the power cord from the unit before replacing any parts. 5) Ensure to insert the disc properly into the unit before use. 6) Since this equipment cannot be used as a standalone unit, it must be installed in a PC (586 or higher) with appropriate device driver from the floppy disk to verify proper operation. 7) This equipment has many parts with properties related to safety. These parts are specifically noted in the parts list and schematic drawings. Ensure to replace these parts with new parts that have the same specifications. - Since the laser diode in the optical pickup bundle can be easily damaged by the static electricity in human body or clothing, use the following grounding guidelines when handling the bundle. Wear a wrist strap with one end properly grounded. The wrist strap discharges the static electricity in human body. Work on a conductive material such as copper plate that is properly grounded. Since the static electricity stored in clothing is not easily discharged, ensure that clothing does not make a contact with the pickup bundle. 1-2. Safety Precautions for Installations A certain semiconductor components are highly susceptible to damages caused by electrostatic discharge (ESD). Semiconductors components such integrated circuits, field effect transistors, and other semiconductor devices are examples of devices that are highly sensitive to ESD. Use the following guidelines to reduce the damages caused by the ESD. 1) Before handling any semiconductor components or parts that contains semiconductors, immediately discharge all static electricity in the body by making a contact with a grounded metallic object. A commercially available wrist strap may also be used. The static electricity must be discharged to avoid potential impact on the voltage during testing. 2) After removing ESD-sensitive components or parts, place the items on a conductive surface such as on a piece of aluminium to prevent accumulation of charges and exposure to ESD. 3) Use properly grounded soldering iron to solder or to de-solder ESD-sensitive components. 4) Only use anti-static soldering iron to de-solder ESD-sensitive components. Use of soldering irons not classified as "anti -static" has enough electrostatic charges to cause damages to the components. 5) Do not use chemical sprays such as Freon. These chemicals have enough electrostatic charges to cause damages to the ESD-sensitive components. 6) Do not remove replacement parts from the anti-static packaging until they are ready for installation. [Most of the replacement parts are packaged in conductive foam, aluminium, or other conductive materials with all the leads shorted together.] 7) Before removing the anti-static packing materials for the new parts, make a contact with the chassis or protective material for the circuits to discharge the static charges. Caution: Ensure that the power does not get transferred to the chassis or to the circuitry, and that all general safety guidelines are followed. 8) Minimize body movement when handling unprotected ESD-sensitive parts and components. (The movement of body causes build up of electrostatic charges from friction between layers of clothing, and between the shoes and the carpet which may cause damage to the components.) 1