AV-A14M3
AV-A14T3
AV-A14AU3
AV-1413EE
SAFETY PRECAUTIONS
1. The design of this product contains special hardware, many9. Isolation Check
circuits and components specially for safety purposes. For(Safety for Electrical Shock Hazard)
continued protection, no changes should be made to the originalAfter re-assembling the product, always perform an isolation
design unless authorized in writing by the manufacturer.check on the exposed metal parts of the cabinet (antenna
Replacement parts must be identical to those used in the originalterminals, video/audio input and output terminals, Control knobs,
circuits. Service should be performed by qualified personnelmetal cabinet, screwheads, earphone jack, control shafts, etc.)
only.to be sure the product is safe to operate without danger of
electrical shock.
2. Alterations of the design or circuitry of the products should not be(1) Dielectric Strength Test
made. Any design alterations or additions will void theThe isolation between the AC primary circuit and all metal parts
manufacturer's warranty and will further relieve the manufacturerexposed to the user, particularly any exposed metal part having a
of responsibility for personal injury or property damage resultingreturn path to the chassis should withstand a voltage of 3000V
therefrom.AC (r.m.s.) for a period of one second.
(. . . . Withstand a voltage of 1100V AC (r.m.s.) to an appliance
3. Many electrical and mechanical parts in the products haverated up to 120V, and 3000V AC (r.m.s.) to an appliance rated
special safety-related characteristics. These characteristics are200V or more, for a period of one second.)
often not evident from visual inspection nor can the protectionThis method of test requires a test equipment not generally found
afforded by them necessarily be obtained by using replacementin the service trade.
components rated for higher voltage, wattage, etc. Replacement(2) Leakage Current Check
parts which have these special safety characteristics arePlug the AC line cord directly into the AC outlet (do not use a line
identified in the parts list of Service manual. Electricalisolation transformer during this check.). Using a "Leakage
components having such features are identified by shadingCurrent Tester", measure the leakage current from each exposed
on the schematics and by ( ) on the parts list in Servicemetal part of the cabinet, particularly any exposed metal part
manual. The use of a substitute replacement which does nothaving a return path to the chassis, to a known good earth
have the same safety characteristics as the recommendedground (water pipe, etc.). Any leakage current must not exceed
replacement part shown in the parts list of Service manual may0.5mA AC (r.m.s.).
cause shock, fire, or other hazards.However, in tropical area, this must not exceed 0.2mA AC
(r.m.s.).
4. Don't short between the LIVE side ground and ISOLATEDzzzz Alternate Check Method
(NEUTRAL) side ground or EARTH side ground whenPlug the AC line cord directly into the AC outlet (do not use a line
repairing.isolation transformer during this check.). Use an AC voltmeter
Some model's power circuit is partly different in the GND. Thehaving 1000 ohms per volt or more sensitivity in the following
difference of the GND is shown by the LIVE : ( ) side GND, themanner. Connect a 1500: 10W resistor paralleled by a 0.15PF
ISOLATED(NEUTRAL) : ( ) side GND and EARTH : ( ) sideAC-type capacitor between an exposed metal part and a known
GND. Don't short between the LIVE side GND andgood earth ground (water pipe, etc.). Measure the AC voltage
ISOLATED(NEUTRAL) side GND or EARTH side GND andacross the resistor with the AC voltmeter. Move the resistor
never measure with a measuring apparatus (oscilloscope etc.)connection to each exposed metal part, particularly any exposed
the LIVE side GND and ISOLATED(NEUTRAL) side GND ormetal part having a return path to the chassis, and measure the
EARTH side GND at the same time.AC voltage across the resistor. Now, reverse the plug in the AC
If above note will not be kept, a fuse or any parts will be broken.outlet and repeat each measurement. Any voltage measured
must not exceed 0.75V AC (r.m.s.). This corresponds to 0.5mA
5. If any repair has been made to the chassis, it is recommendedAC (r.m.s.).
that the B1 setting should be checked or adjusted (SeeHowever, in tropical area, this must not exceed 0.3V AC (r.m.s.).
ADJUSTMENT OF B1 POWER SUPPLY).This corresponds to 0.2mA AC (r.m.s.).
6. The high voltage applied to the picture tube must conform with
AC VOLTMETER
that specified in Service manual. Excessive high voltage can(HAVING 1000 :/V,
cause an increase in X-Ray emission, arcing and possibleOR MORE SENSITIVITY)
component damage, therefore operation under excessive high
voltage conditions should be kept to a minimum, or should be
prevented. If severe arcing occurs, remove the AC power
immediately and determine the cause by visual inspection0.15 F AC-TYPE
(incorrect installation, cracked or melted high voltage harness,
poor soldering, etc.). To maintain the proper minimum level ofPLACE THIS PROBE
soft X-Ray emission, components in the high voltage circuitryON EACH EXPOSED
including the picture tube must be the exact replacements or1500 : 10WMETAL PART
alternatives approved by the manufacturer of the completeGOOD EARTH GROUND
product.
11. High voltage hold down circuit check. For AV-A14M3(U)
7. Do not check high voltage by drawing an arc. Use a high voltage
meter or a high voltage probe with a VTVM. Discharge theAfter repair of the high voltage hold down circuit, this circuit shall
be checked to operate correctly.
picture tube before attempting meter connection, by connecting
See item "How to check the high voltage hold down circuit".
a clip lead to the ground frame and connecting the other end of
the lead through a 10k: 2W resistor to the anode button.
8. When service is required, observe the original lead dress. Extra
precaution should be given to assure correct lead dress in the
high voltage circuit area. Where a short circuit has occurred,
those components that indicate evidence of overheating should
be replaced. Always use the manufacturer's replacement
components.
No.516693 |
ACEC
