1. Precautions
1-1 Safety Precautions
1. Be sure that all of the built-in protective devices are5. With the unit completely reassembled, plug the AC
replaced. Restore any missing protective shields.line cord directly the power outlet. With the unit?s
AC switch first in the ON position and then OFF,
2. When reinstalling the chassis and its assemblies, bemeasure the current between a known erath
sure to restore all pretective devices, including :ground (metal water pipe, conduit, etc.) and all
control knobs and compartment covers.exposed metal parts, including : antennas, handle
brackets, metal cabinets, screwheads and control
3. Make sure that there are no cabinet openingsshafts. The current measured should not exceed
through which people--particularly children --0.5 milliamp. Reverse the power-plug prongs in the
might insert fingers and contact dangerous AC outlet and repeat the test.
voltages. Such openings include the spacing
between the picture tube and the cabinet mask,6. Antenna Cold Check :
excessively wide cabinet ventilation slots, andWith the unit?s AC plug disconnected from the
improperly fitted back covers.AC source, connect an electrical jumper across the
two AC prongs. Connect one lead of the ohmmeter
If the measured resistance is less than 1.0 megohmto an AC prong.
or greater than 5.2 megohms, an abnormality existsConnect the other lead to the coaxial connector.
that must be corrected before the unit is returned
to the customer.7. Some semiconductor (?solid state?) devices are
easily damaged by static electricity.
4. Leakage Current Hot Check (See Fig. 1-1) :Such components are called Electrostatically
Warning : Do not use an isolation transformer Sensitive Devices (ESDs); examples include
during this test. Use a leakage current tester or aintegrated circuits and some field-effect transistors.
metering system that complies with AmericanThe following techniques will reduce the
National Standards Institute (ANSI C101.1, occurrence of component damage caused by static
Leakage Current for Appliances), and Underwriterselectricity.
Laboratories (ULPublication UL1410, 59.7).
8. Immediately before handling sny semiconductor
components or assemblies, drain the electrostatic
(READING SHOULD
charge from your body by touching a known
NOT BE ABOVE
0.5mA)earth ground. Alternatively, wear a discharging
LEAKAGE
DEVICECURRENTWrist-strap device. (Be sure to remove it prior to
UNDERTESTER
applying power--this is an electric shock
TEST
precaution.)
TEST ALL
EXPOSED METER
SURFACES9. Design Alteration Warning :
Never alter or add to the mechanical or electrical
2-WIRE CORD
design of this unit. Example : Do not add
ALSO TEST WITHauxiliary audio or video connectors.
EARTH
PLUG REVERSED
GROUND
(USING AC ADAPTERSuch alterations might create a safety hazard.
PLUG AS REQUIRED)Also, any design changes or additions will void
the manufacturer?s warranty.
Fig. 1-1 AC Leakage Test
10. Never defeat any of the B+ voltage interlocks.
Do not apply AC power to the unit (or any of its
assemblies) unless all solid-state heat sinks are
correctly installed.
Samsung Electronics1-1 |
ACEC
SAMSUNG
