Also, because the picture tube shields and an isolation transformer only if the AC power
mounting hardware perform an X-radiation plug is inserted so that the chassis is
protection function, they must be correctly in connected to the ground side of the AC power
place. High voltage must be measured each source. To confirm that the AC power plug is
time servicing is performed that involves B+, inserted correctly, with an AC voltmeter,
horizontal deflection or high voltage. Correct measure between the chassis and a known
operation of the X-radiation protection circuits earth ground. If a voltage reading in excess of
also must be reconfirmed each time they are 1.0V is obtained, remove and reinsert the AC
serviced. (X-radiation protection circuits also power plug in the opposite polarity and again
may be called ?horizontal disable? or ?hold measure the voltage potential between the
down.?) Read and apply the high voltage limits chassis and a known earth ground.
and, if the chassis is so equipped, the X-
radiation protection circuit specifications given b. Some TV receiver chassis normally have 85V
on instrument labels and in the Product Safety AC(RMS) between chassis and earth ground
& X-Radiation Warning note on the service regardless of the AC plug polarity. This chassis
data chassis schematic. High voltage is can be safety-serviced only with an isolation
maintained within specified limits by close transformer inserted in the power line between
the receiver and the AC power source, for both
tolerance safety-related components/personnel and test equipment protection.
adjustments in the high-voltage circuit. If high c. Some TV receiver chassis have a secondary
voltage exceeds specified limits, check each ground system in addition to the main chassis
component specified on the chassis schematic ground. This secondary ground system is not
and take corrective action.isolated from the AC power line. The two
2. Read and comply with all caution and safety-ground systems are electrically separated by
related notes on or inside the receiver cabinet, on insulation material that must not be defeated or
the receiver chassis, or on the picture tube.altered.
3. Design Alteration Warning - Do not alter or add
to the mechanical or electrical design of this TV 6. Observe original lead dress. Take extra care to
receiver. Design alterations and additions, assure correct lead dress in the following areas: a.
including, but not limited to circuit modifications near sharp edges, b. near thermally hot parts-be
sure that leads and components do not touch
and the addition of items such as auxiliary audio thermally hot parts, c. the AC supply, d. high
and/or video output connections, might alter the voltage, and, e. antenna wiring. Always inspect in
safety characteristics of this receiver and create a all areas for pinched, out of place, or frayed wiring.
hazard to the user. Any design alterations or Check AC power cord for damage.
additions will void the manufacturer's warranty and 7. Components, parts, and/or wiring that appear to
may make you, the servicer, responsible for have overheated or are otherwise damaged
personal injury or property damage resulting should be replaced with components, parts, or
therefrom.wiring that meet original specifications.
4. Picture Tube Implosion Protection Warning - Additionally, determine the cause of overheating
The picture tube in this receiver employs integral and/or damage and, if necessary, take corrective
implosion protection. For continued implosion action to remove any potential safety hazard.
protection, replace the picture tube only with one
of the same type number. Do not remove, install, 8. Product Safety Notice - Some electrical and
or otherwise handle the picture tube in any mechanical parts have special safety-related
manner without first putting on shatterproof characteristics which are often not evident from
goggles equipped with side shields. People not so visual inspection, nor can the protection they give
equipped must be kept safely away while picture necessarily be obtained by replacing them with
components rated for higher voltage, wattage, etc..
tubes are handled. Keep the picture tube away Parts that have special safety characteristics are
from your body. Do not handle the picture tube by identified by a # on schematics and in parts lists.
its neck. Some ?in-line? picture tubes are equipped Use of a substitute replacement that does not
with a permanently attached deflection yoke; have the same safety characteristics as the
because of potential hazard, do not try to remove recommended replacement part might create
such ?permanently attached? yokes from the shock, fire, and/or other hazards. The product's
picture tube.safety is under review continuously and new
5. Hot Chassis Warning -instructions are issued whenever appropriate.
a. Some TV receiver chassis are electrically Prior to shipment from the factory, our products
connected directly to one conductor of the AC are strictly inspected to confirm they comply with
power cord and maybe safety-serviced without the recognized product safety and electrical codes
2-2TVN_ISP |
ACEC
