Sharp LC-13SH1U Service Manual page 5

specifications given on instrument labels and in the
Product Safety & X-Radiation Warning note on the
service data chassis schematic. High voltage is
maintained within specified limits by close tolerance
safety-related components/adjustments in the high-
voltage circuit. If high voltage exceeds specified
limits, check each component specified on the chassis
schematic and take corrective action.
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
connections, might alter the safety characteristics of
this receiver and create a hazard to the user. Any
design alterations or additions will void the
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. For continued implosion 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. Some "in-line" picture tubes
are equipped with a permanently attached deflection
yoke; because of potential hazard, do not try to
remove such "permanently attached" yokes from
the picture tube.
5. Hot Chassis Warning -
a. Some TV receiver chassis are electrically connected
directly to one conductor of the AC power cord and
maybe safety-serviced without an isolation
transformer only if the AC power plug is inserted so
that the chassis is connected to the ground side of
the AC power source. To confirm that the AC power
plug is inserted correctly, with an AC voltmeter,
measure 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. This chassis can
be safety-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 insulation material that
must not be defeated or altered.
6. Observe original lead dress. Take extra care to
assure correct lead dress 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,c. the AC supply,d. high voltage,
and,e. antenna wiring. Always inspect in all areas for
pinched, out of place, or frayed wiring. 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 overheating and/or damage and, if
necessary, take corrective action to remove any
potential safety hazard.
8. 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 a ( # ) on schematics and in 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. The product's safety is under review
continuously and new instructions are issued
whenever appropriate. Prior to shipment from the
factory, our products are strictly inspected to confirm
they comply with the recognized product safety and
electrical codes of the countries in which they are to
be sold. However, in order to maintain such
compliance, it is equally important to implement the
following precautions when a set is being serviced.
2-2
LCVISP