AV-16N8
SAFETY PRECAUTIONS
1. The design of this product contains special hardware, many8. When service is required, observe the original lead dress. Ex-
circuits and components specially for safety purposes. For con-tra precaution should be given to assure correct lead dress in
tinued protection, no changes should be made to the originalthe high voltage circuit area. Where a short circuit has occurred,
design unless authorized in writing by the manufacturerthose components that indicate evidence of overheating should. Re-
placement parts must be identical to those used in the originalbe replaced. Always use the manufacturer's replacement com-
circuits. Service should be performed by qualified personnelponents.
only.
9. Isolation Check
2. Alterations of the design or circuitry of the products should not(Safety for Electrical Shock Hazard)
be made. Any design alterations or additions will void theAfter re-assembling the product, always perform an isolation
manufacturer's warranty and will further relieve the manufac-check on the exposed metal parts of the cabinet (antenna ter-
turer of responsibility for personal injury or property damageminals, video/audio input and output terminals, Control knobs,
resulting therefrom.metal cabinet, screw heads, earphone jack, control shafts, etc.)
to be sure the product is safe to operate without danger of elec-
3. Many electrical and mechanical parts in the products have spe-trical shock.
cial safety-related characteristics. These characteristics are of-(1)Dielectric Strength Test
ten not evident from visual inspection nor can the protectionThe isolation between the AC primary circuit and all metal parts
afforded by them necessarily be obtained by using replace-exposed to the user, particularly any exposed metal part hav-
ment components rated for higher voltage, wattage, etc. Re-ing a return path to the chassis should withstand a voltage of
placement parts which have these special safety characteris-3000V AC (r.m.s.) for a period of one second.
tics are identified in the parts list of Service manual. Electrical(. . . . Withstand a voltage of 1100V AC (r.m.s.) to an appliance
components having such features are identified by shad-rated up to 120V, and 3000V AC (r.m.s.) to an appliance rated
ing on the schematics and by (!) on the parts list in Ser- 200V or more, for a period of one second.)
vice manual. The use of a substitute replacement which doesThis method of test requires a test equipment not generally
not have the same safety characteristics as the recommendedfound in the service trade.
replacement part shown in the parts list of Service manual may(2)Leakage Current Check
cause shock, fire, or other hazards.Plug the AC line cord directly into the AC outlet (do not use a
line isolation transformer during this check.). Using a "Leakage
4. Don't short between the LIVE side ground and ISOLATED Current Tester", measure the leakage current from each ex-
(NEUTRAL) side ground or EARTH side ground when re-posed metal part of the cabinet, particularly any exposed metal
pairing.part having a return path to the chassis, to a known good earth
Some model's power circuit is partly different in the GND. ground (water pipe, etc.). TheAny leakage current must not exceed
difference of the GND is shown by the LIVE : (#) side GND,0.5mA AC (r.m.s.).
the ISOLATED (NEUTRAL) : (") side GND and EARTH : ($)However, in tropical area, this must not exceed 0.2mA AC
side GND. Don't short between the LIVE side GND and ISO-(r.m.s.).
LATED (NEUTRAL) side GND or EARTH side GND and neverl Alternate Check Method
measure with a measuring apparatus (oscilloscope etc.) thePlug the AC line cord directly into the AC outlet (do not use a
LIVE side GND and ISOLATED (NEUTRAL) side GND orline isolation transformer during this check.). Use an AC volt-
EARTH side GND at the same time.meter having 1000 ohms per volt or more sensitivity in the fol-
If above note will not be kept, a fuse or any parts will be bro-lowing manner. Connect a 1500W 10W resistor paralleled by a
ken.0.15mF AC-type capacitor between an exposed metal part and
a known good earth ground (water pipe, etc.). Measure the AC
5. If any repair has been made to the chassis, it is recommendedvoltage across the resistor with the AC voltmeter. Move the
that the B1 setting should be checked or adjusted (See resistor connection to each exposed metal part, particularly anyAD-
JUSTMENT OF B1 POWER SUPPLY).exposed metal part having a return path to the chassis, and
measure the AC voltage across the resistor. Now, reverse the
6. The high voltage applied to the picture tube must conform withplug in the AC outlet and repeat each measurement. Any volt-
that specified in Service manual. Excessive high voltage canage measured must not exceed 0.75V AC (r.m.s.). This corre-
cause an increase in X-Ray emission, arcing and possible com-sponds to 0.5mA AC (r.m.s.).
ponent damage, therefore operation under excessive high volt-However, in tropical area, this must not exceed 0.3V AC (r.m.s.).
age conditions should be kept to a minimum, or should be pre-This corresponds to 0.2mA AC (r.m.s.).
vented. If severe arcing occurs, remove the AC power immedi-
ately and determine the cause by visual inspection (incorrectAC VOLTMETER
installation, cracked or melted high voltage harness, poor sol-(HAVING 1000W/V,
dering, etc.). To maintain the proper minimum level of soft X-OR MORE SENSITIVITY)
Ray emission, components in the high voltage circuitry includ-
ing the picture tube must be the exact replacements or alterna-
tives approved by the manufacturer of the complete product.
7. Do not check high voltage by drawing an arc. Use a high volt-0.15mF AC-TYPE
age meter or a high voltage probe with a VTVM. Discharge the
picture tube before attempting meter connection, by connect-PLACE THIS PROBE
ON EACH EXPOSED
ing a clip lead to the ground frame and connecting the other
1500W 10W
METAL PART
end of the lead through a 10kW 2W resistor to the anode but-
ton.GOOD EARTH GROUND
No. 560943 |
ACEC
