Text preview for : 03_Precations.pdf part of Samsung 03 Precations Samsung Audio HT-P1200 HT-P1200 03_Precations.pdf
Back to : 03_Precations.pdf | Home
1. Precautions
Follow these safety, servicing and ESD precautions to prevent damage and protect against potential hazards
such as electrical shock and X-rays.
1-1 Safety Precautions
1. Be sure that all of the built-in protective
devices are replaced.
2. When reinstalling the chassis and its
assemblies, be sure to restore all protective
devices, including control knobs and
compartment covers.
3. Make sure that there are no cabinet
openings through which people--
particularly children--might insert fingers
and contact dangerous voltages. Such
openings include the spacing between the
picture tube and the cabinet mask,
excessively wide cabinet ventilation slots,
and improperly fitted back covers. Fig. 1-1 AC Leakage Test
4. Design Alteration Warning: 6. Insulation Resistance Cold Check:
Never alter or add to the mechanical or (1) With the unit's AC plug disconnected
electrical design of the unit. Example: Do from the AC source, connect an electrical
not add auxiliary audio or video connec- jumper across the two AC prongs. (2) Set
tors. Such alterations might create a safety the power switch to ON. (3) Measure the
hazard. Also, any design changes or addi- resistance between the shorted AC plug and
tions will void the manufacturer's warran- any exposed metallic parts. Example:
ty. Screwheads, antenna, control shafts or
handle brackets.
5. Leakage Current Hot Check (Figure 1-1):
Warning: Do not use an isolation If any of the exposed metallic parts has a
transformer during this test. Use a leakage- return path to the chassis, the measured
current tester or a metering system that resistance should be between 1 and 5.2
complies with American National Standards megohms. If there is no return path, the
Institute (ANSI C101.1, Leakage Current for measured resistance should be "infinite." If
Appliances), and Underwriters Laboratories the resistance is outside these limits, a shock
(UL Publication UL1410, 59.7). hazard might exist. See Figure 1-2
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. The current measured should not
exceed 0.5 milliamp. Reverse the power-
plug prongs in the AC outlet and repeat.
Fig. 1-2 Insulation Resistance Test
Samsung Electronics 1-1
Precautions
1-1 Safety Precautions (Continued)
7. Components, parts and wiring that appear 9. Product Safety Notice:
to have overheated or that are otherwise Some electrical and mechanical parts
damaged should be replaced with parts have special safety-related characteristics
that meet the original specifications. which might not be obvious from visual
Always determine the cause of damage or inspection. These safety features and the
overheating, and correct any potential protection they give might be lost if the
hazards replacement component differs from the
original--even if the replacement is rated
8. Observe the original lead dress, especially for higher voltage, wattage, etc.
near the following areas: Antenna
wiring, sharp edges, and especially the 10 Components that are critical for safety are
AC and high voltage power supplies. indicated in the circuit diagram by
Always inspect for pinched, out-of-place, shading, or . Use replacement
or frayed wiring. Do not change the components that have the same ratings,
spacing between components and the especially for flame resistance and
printed circuit board. Check the AC dielectric strength specifications. A
power cord for damage. Make sure that replacement part that does not have the
no wires or components touch thermally same safety characteristics as the original
hot parts. might create shock, fire or other hazards.
1-2 Servicing Precautions
Warning1: First read the "Safety Precautions" section of this manual. If some unforeseen circumstance creates a conflict
between the servicing and safety precautions, always follow the safety precautions.
1. Servicing precautions are printed on the 5. Check the insulation between the blades of
cabinet. Follow them. the AC plug and accessible conductive parts
(examples: metal panels, input terminals
2. Always unplug the unit's AC power cord and earphone jacks).
from the AC power source before
attempting to: (a) Remove or reinstall any 6. Insulation Checking Procedure: Disconnect
component or assembly, (b) Disconnect an the power cord from the AC source and
electrical plug or connector, (c) Connect a turn the power switch ON. Connect an
test component in parallel with an insulation resistance meter (500V) to the
electrolytic capacitor. blades of the AC plug.
3. Some components are raised above the The insulation resistance between each
printed circuit board for safety. An blade of the AC plug and accessible
insulation tube or tape is sometimes used. conductive parts (see above) should be
The internal wiring may be clamped to greater than 1 megohm.
prevent contact with thermally hot
components. Reinstall all such elements to 7. Never defeat any of the B+ voltage
their original position. interlocks. Do not apply AC power to the
unit (or any of its assemblies) unless all
4. After servicing, always check that the solid-state heat sinks are correctly installed.
screws, components and wiring have been
correctly reinstalled. Make sure that the 8. Always connect a test instrument's ground
portion around the serviced part has not lead to the instrument chassis ground
been damaged. before connecting the positive lead; always
remove the instrument's ground lead last.
1-2 Samsung Electronics
Precautions
1-3 Precautions for Electrostatically Sensitive Devices (ESDs)
1. Some semiconductor ("solid state") devices 5. Use only a grounded-tip soldering iron
are easily damaged by static electricity. when soldering or unsoldering ESDs.
Such components are called Electrostatically
Sensitive Devices (ESDs). Examples include 6. Use only an anti-static solder removal
integrated circuits and some field-effect device. Many solder removal devices are
transistors. The following techniques will not rated as "anti-static" (these can
reduce the occurrence of component accumulate sufficient electrical charge to
damage caused by static electricity. damage ESDs).
2. Immediately before handling any 7. Do not remove a replacement ESD from its
semiconductor components or assemblies, protective package until you are ready to
drain the electrostatic charge from your install it. Most replacement ESDs are
body by touching a known earth ground. packaged with leads that are electrically
Alternatively, wear a discharging shorted together by conductive foam,
wrist-strap device. (Be sure to remove it aluminum foil or other conductive
prior to applying power--this is an electric materials.
shock precaution.)
8. Immediately before removing the protective
3. After removing an ESD-equipped assembly, material from the leads of a replacement
place it on a conductive surface such as ESD, touch the protective material to the
aluminum foil to prevent accumulation of chassis or circuit assembly into which the
electrostatic charge. device will be installed.
4. Do not use freon-propelled chemicals. 9. Minimize body motions when handing
These can generate electrical charges that unpackaged replacement ESDs. Motions
damage ESDs. such as brushing clothes together, or lifting
a foot from a carpeted floor can generate
enough static electricity to damage an ESD.
1-4 Special Precautions and Warning Labels for Laser Products
(UL) (CSA) (UL,CSA,EU)
This Product Complies with CERTIFIED ONLY TO CANADIAN
DHHS Rules 21CFR, Sub ELECTRICAL CODE.
chapter J.At date of Manu- CLASS 1
facture CERTIFIE EN VERTU DU CODE LASER PRODUCT
CANADIAN DE LELETRICITE
SEULEMENT
Fig. 1-3 Warning Labels (Location: Enclosure Block)
(UL,CSA,SCAN)
CAUTION : INVISIBLE LASER RADIATION WHEN OPEN
AND INTERLOCKS DEFEATEO AVOIDEXPOSURE TO BEAM
ADVARSEL: USYNLIG LASERSTR