Hitachi C47-WD7000 Service Manual page 5

SAFETY PRECAUTIONS
2. Read and comply with all caution and safety-related
notes on or inside the receiver cabinet, on the
receiver chassis, or on the picture tube.
3. Design Alteration Warning - Do not alter or add to
the mechanical or electrical design of this TV receiver.
Design alterations and additions, including but not
limited to circuit modifications and the addition of
items such as auxiliary audio and/or video output
connectors, might alter the safety characteristics of
this receiver and create a hazard to the user. Any
design alterations or
manufacturer's warranty and may make you, the
servicer, responsible for personal injury or property
damage resulting therefrom.
4. Picture Tube Implosion Protection Warning - The
picture tube in this receiver employs integral
implosion protection.
protection, replace the picture tube only with one of
the same type number. Do not remove, install, or
otherwise handle the picture tube in any manner
without first putting on shatterproof goggles equipped
with side shields. People not so equipped must be
kept safely away while picture tubes are handled.
Keep the picture tube away from your body. Do not
handle the picture tube by its neck.
5. Hot Chassis Warning
a) Some TV receiver chassis are electrically connected
directly to one conductor of the AC power cord and
may be safely serviced
transformer only if the AC power plug is inserted so
that the chassis is connected to the ground side of the
AC power source. Confirm that the AC power plug is
inserted correctly with an AC voltmeter by measuring
between the chassis and a known earth ground. If a
voltage reading in excess of 1.0V is obtained, remove
and reinsert the AC power plug in the opposite polarity
and again measure the voltage potential between the
chassis and a known earth ground.
b) Some TV receiver chassis normally have 85V AC
(RMS) between chassis and earth ground regardless
of the AC plug polarity. These chassis can be safely
serviced only with an isolation transformer inserted in
the power line between the receiver and the AC power
source, for both personnel and test equipment
protection.
c) Some TV receiver chassis have a secondary ground
system in addition to the main chassis ground. This
secondary ground system is not isolated from the AC
power line. The two ground systems are electrically
separated by insulating material that must not be
defeated or altered.
additions may void
For continued implosion
without an isolation
6. Observe original lead dress. Take extra care to assure
correct lead dress (the AC supply, high voltage and
antenna wiring) in the following areas:
a) Near sharp edges
b) Near thermally hot parts
Be sure that leads and components do not touch
thermally hot parts. Always inspect in all areas for
pinched, out-of -plate, or frayed wiring; Do not
change spacing between components and the printed
the circuit board; Check AC power cord for damage.
7. Components, parts, and/or wiring that appear to have
overheated or are otherwise damaged should be
replaced with components, parts or wiring that meet
original specifications. Additionally, determine the
cause of
necessary, take corrective action to remove any
potential safety hazard.
8. PRODUCT SAFETY NOTICE - Many TV electrical
and mechanical parts have special safety-related
characteristics some of 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 a
substitute replacement that does not have the same
safety characteristics
replacement part in the parts list might create shock,
fire, and/or other hazards. Product safety is under
review continuously and new instructions are issued
whenever appropriate. For the latest information,
always consult the appropriate current service
literature. A subscription to, or additional copies of
service literature may be obtained at a nominal
charge from manufacturer.
5
overheating and/or damage
in the replacement parts list. Use of
!
as the
and, if
recommended