Precautions
1-1 Safety Precautions (Continued)
9. High voltage is maintained within specified15. Observe the original lead dress, especially
limits by close-tolerance, safety-related near the following areas: Antenna wiring,
sharp edges, and especially the AC and high
components and adjustments. If the high voltage power supplies. Always inspect for
voltage exceeds the specified limits, check
each of the special components. pinched, out-of-place, or frayed wiring. Do
not change the spacing between components
10. Design Alteration Warning:and the printed circuit board. Check the AC
Never alter or add to the mechanical or power cord for damage. Make sure that leads
electrical design of this unit. Example: Do notand components do not touch thermally hot
add auxiliary audio or video connectors. Suchparts.
alterations might create a safety hazard. Also,
any design changes or additions will void the16. Picture Tube Implosion Warning:
manufacturerOs warranty.The picture tube in this receiver employs
Ointegral implosion� protection. To ensure
11. Hot Chassis Warning:continued implosion protection, make sure
Some TV receiver chassis are electrically that the replacement picture tube is the same
connected directly to one conductor of the ACas the original.
power cord. If an isolation transformer is not
used, these units may be safely serviced only17. Do not remove, install or handle the picture
if the AC power plug is inserted so that thetube without first putting on shatterproof
chassis is connected to the ground side of thegoggles equipped with side shields. Never
AC source. handle the picture tube by its neck. Some
Oin-line� picture tubes are equipped with a
To confirm that the AC power plug is inserted
correctly, do the following: Using an AC permanently attached deflection yoke; do not
try to remove such Opermanently attached�
voltmeter, measure the voltage between the yokes from the picture tube.
chassis and a known earth ground. If the
reading is greater than 1.0V, remove the AC18. Product Safety Notice:
power plug, reverse its polarity and reinsert.
Re-measure the voltage between the chassisSome electrical and mechanical parts have
special safety-related characteristics which
and ground. might not be obvious from visual inspection.
These safety features and the protection they
12. Some TV chassis are designed to operate withgive might be lost if the replacement
85 volts AC between chassis and ground,
regardless of the AC plug polarity. These unitscomponent differs from the originalNeven if
can be safely serviced only if an isolationthe replacement is rated for higher voltage,
wattage, etc.
transformer inserted between the receiver and
the power source.
Components that are critical for safety are
13. Some TV chassis have a secondary groundindicated in the circuit diagram by shading,
system in addition to the main chassis ground.( ) or ( ). !
This secondary ground system is not Use replacement components that have the
isolated from the AC power line. The twosame ratings, especially for flame resistance
ground systems are electrically separated byand dielectric strength specifications.
insulating material that must not be defeatedA replacement part that does not have the
or altered.same safety characteristics as the original
might create shock, fire or other hazards.
14. Components, parts and wiring that appear to
have overheated or that are otherwise
damaged should be replaced with parts that
meet the original specifications. Always
determine the cause of damage or
overheating, and correct any potential
hazards.
1-2 |
ACEC
