SAMSUNG DVD-E218 Service Manual Precaution

Samsung Electronics 1-1
1. Precautions
1-1 Safety Precautions
1) Before returning an instrument to the customer, always make a safety check of the entire instrument, including, but not limited to, the following items:
(1) Be sure that no built-in protective devices are
(2) Be sure that there are no cabinet openings through
which adults or children might be able to insert their fingers and contact a hazardous voltage. Such openings include, but are not limited to, excessive­ly wide cabinet ventilation slots, and an improper­ly fitted and/or incorrectly secured cabinet back cover.
(3) Leakage Current Hot Check-With the instrument
completely reassembled, plug the AC line cord directly into a 120V AC outlet. (Do not use an iso­lation transformer during this test.) Use am leakage current tester or a metering system that complies with American National Standards institute (ANSI) C101.1 Leakage Current for Appliances and Underwriters Laboratories (UL) 1270 (40.7). With the instrument’s AC switch first in the ON position and then in the OFF position, measure from a known earth ground (metal water pipe, conduit, etc.) to all exposed metal parts of the instrument (antennas, handle brackets, metal cabinets, screw­heads, metallic overlays, control shafts, etc.), espe­cially any exposed metal parts that offer an electri­cal return path to the chassis.
Any current measured must not exceed 0.5mA. Reverse the instrument power cord plug in the out­let and repeat the test. See Fig. 1-1.
Any measurements not within the limits specified herein indicate a potential shock hazard that must be eliminated before returning the instrument to the customer.
Fig. 1-1 AC Leakage Test
(4) Insulation Resistance Test Cold Check-(1) Unplug
the power supply cord and connect a jumper wire between the two prongs of the plug. (2) Turn on the power switch of the instrument. (3) Measure the resistance with an ohmmeter between the jumpered AC plug and all exposed metallic cabinet parts on the instrument, such as screwheads, antenna, control shafts, handle brackets, etc. When an exposed metallic part has a return path to the chassis, the reading should be between 1 and 5.2 megohm. When there is no return path to the chas­sis, the reading must be infinite. If the reading is not within the limits specified, there is the possibil­ity of a shock hazard, and the instrument must be repaired and rechecked before it is returned to the customer. See Fig. 1-2.
Fig. 1-2 Insulation Resistance Test
DEVICE UNDER
TEST
(READING SHOULD
NOT BE ABOVE
0.5mA)
LEAKAGE CURRENT
TESTER
EARTH
GROUND
TEST ALL
EXPOSED METER
SURFACES
ALSO TEST WITH
PLUG REVERSED
(USING AC ADAPTER
PLUG AS REQUIRED)
2-WIRE CORD
Antenna Terminal
Exposed Metal Part
ohm
ohmmeter
Precautions
1-2 Samsung Electronics
2) Read and comply with all caution and safety re­lated notes on inside the cabinet, or on the chassis.
3) Design Alteration Warning-Do not alter or add to the mechanical or electrical design of this instru­ment. Design alterations and additions, including but not limited to, circuit modifications and the addition of items such as auxiliary audio output connections, might alter the safety characteristics of this instrument and create a hazard to the user. Any design alterations or additions will make you, the servicer, responsible for personal injury or property damage resulting therefrom.
4) Observe original lead dress. Take extra care to assure correct lead dress in the following areas: (1) near sharp edges, (2) near thermally hot parts (be sure that leads and components do not touch ther­mally hot parts), (3) the AC supply, (4) high voltage, and (5) antenna wiring. Always inspect in all areas for pinched, out-of-place, or frayed wiring, Do not change spacing between a component and the printed-circuit board. Check the AC power cord for damage.
5) Components, parts, and/or wiring that appear to have overheated or that are otherwise damaged should be replaced with components, parts and/ or wiring that meet original specifications. Additionally, determine the cause of overheating and/or damage and, if necessary, take corrective action to remove any potential safety hazard.
6) Product Safety Notice-Some electrical and mechani­cal parts have special safety-related characteristics which are often not evident from visual inspection, nor can the protection they give necessarily be obtained by replacing them with components rated for higher voltage, wattage, etc. Parts that have spe­cial safety characteristics are identified by shading, an ( )or a ( )on schematics and parts lists. Use of a substitute replacement that does not have the same safety characteristics as the recommended replacement part might create shock, fire and/or other hazards. Product safety is under review con­tinuously and new instructions are issued whenev­er appropriate.
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