AV-36D202
AV-36D302
AV-36D502
SAFETY PRECAUTIONS
1. The design of this product contains special hardware, many circuits10.Isolation Check
and components specially for safety purposes. For continued pro-(Safety for Electrical Shock Hazard)
tection, no changes should be made to the original design unlessAfter re-assembling the product, always perform an isolation check
authorized in writing by the manufacturer. Replacement parts muston the exposed metal parts of the cabinet (antenna terminals, video/
be identical to those used in the original circuits. Service should beaudio input and output terminals, Control knobs, metal cabinet,
performed by qualified personnel only.screwheads, earphone jack, control shafts, etc.) to be sure the prod-
2. Alterations of the design or circuitry of the products should not beuct is safe to operate without danger of electrical shock.
made. Any design alterations or additions will void the manufactur-(1) Dielectric Strength Test
er's warranty and will further relieve the manufacturer of responsi-The isolation between the AC primary circuit and all metal parts
bility for personal injury or property damage resulting therefrom.exposed to the user, particularly any exposed metal part having a
3. Many electrical and mechanical parts in the products have specialreturn path to the chassis should withstand a voltage of 1100V AC
safety-related characteristics. These characteristics are often not(r.m.s.) for a period of one second.
evident from visual inspection nor can the protection afforded by(. . . . Withstand a voltage of 1100V AC (r.m.s.) to an appliance rated
them necessarily be obtained by using replacement componentsup to 120V, and 3000V AC (r.m.s.) to an appliance rated 200V or
rated for higher voltage, wattage, etc. Replacement parts which havemore, for a period of one second.)
these special safety characteristics are identified in the parts list ofThis method of test requires a test equipment not generally found in
Service manual. Electrical components having such features arethe service trade.
identified by shading on the schematics and by ( ) on the(2) Leakage Current Check
parts list in Service manual. The use of a substitute replacementPlug the AC line cord directly into the AC outlet (do not use a line
which does not have the same safety characteristics as the recom-isolation transformer during this check.). Using a OLeakage Current
mended replacement part shown in the parts list of Service manualTester�, measure the leakage current from each exposed metal part
may cause shock, fire, or other hazards.of the cabinet, particularly any exposed metal part having a return
4. Use isolation transformer when hot chassis.path to the chassis, to a known good earth ground (water pipe, etc.).
The chassis and any sub-chassis contained in some products areAny leakage current must not exceed 0.5mA AC (r.m.s.).
connected to one side of the AC power line. An isolation transformerHowever, in tropical area, this must not exceed 0.2mA AC (r.m.s.).
of adequate capacity should be inserted between the product andY Alternate Check Method
the AC power supply point while performing any service on somePlug the AC line cord directly into the AC outlet (do not use a line
products when the HOT chassis is exposed.isolation transformer during this check.). Use an AC voltmeter hav-
5. Don't short between the LIVE side ground and ISOLATED (NEU-ing 1000 ohms per volt or more sensitivity in the following manner.
TRAL) side ground or EARTH side ground when repairing.Connect a 1500O 10W resistor paralleled by a 0.15?F AC-type ca-
Some model's power circuit is partly different in the GND. The dif-pacitor between an exposed metal part and a known good earth
ference of the GND is shown by the LIVE : ( ) side GND, theground (water pipe, etc.). Measure the AC voltage across the resis-
ISOLATED(NEUTRAL) : ( ) side GND and EARTH : ( ) sidetor with the AC voltmeter. Move the resistor connection to each ex-
GND. Don't short between the LIVE side GND andposed metal part, particularly any exposed metal part having a re-
ISOLATED(NEUTRAL) side GND or EARTH side GND and neverturn path to the chassis, and measure the AC voltage across the
measure with a measuring apparatus (oscilloscope etc.) the LIVEresistor. Now, reverse the plug in the AC outlet and repeat each
side GND and ISOLATED(NEUTRAL) side GND or EARTH sidemeasurement. Any voltage measured must not exceed 0.75V AC
GND at the same time.(r.m.s.). This corresponds to 0.5mA AC (r.m.s.).
If above note will not be kept, a fuse or any parts will be broken.However, in tropical area, this must not exceed 0.3V AC (r.m.s.).
6. If any repair has been made to the chassis, it is recommended thatThis corresponds to 0.2mA AC (r.m.s.).
the B1 setting should be checked or adjusted (See ADJUSTMENT
AC VOLTMETER
OF B1 POWER SUPPLY).
(HAVING 1000O/V,
7. The high voltage applied to the picture tube must conform with thatOR MORE SENSITIVITY)
GOOD
specified in Service manual. Excessive high voltage can cause an
EARTH
increase in X-Ray emission, arcing and possible component dam-GROUND
0.15 ?F AC-TYPE
age, therefore operation under excessive high voltage conditions
PLACE THIS PROBE
should be kept to a minimum, or should be prevented. If severe
ON EACH EXPOSED
arcing occurs, remove the AC power immediately and determineMETAL PART
1500O 10W
the cause by visual inspection (incorrect installation, cracked or
melted high voltage harness, poor soldering, etc.). To maintain the
11. High voltage hold down circuit check.
proper minimum level of soft X-Ray emission, components in the
After repair of the high voltage hold down circuit, this circuit shall be
high voltage circuitry including the picture tube must be the exact
checked to operate correctly.
replacements or alternatives approved by the manufacturer of the
See item OHow to check the high voltage hold down circuit�.
complete product.
8. Do not check high voltage by drawing an arc. Use a high voltage
This mark shows a fastPOWER CORD
meter or a high voltage probe with a VTVM. Discharge the picture
operating fuse, theREPLACEMENT WARNING
tube before attempting meter connection, by connecting a clip lead
letters indicated belowConnecting thr white line side of
to the ground frame and connecting the other end of the lead through
show the rating.power cord to OWHT� character side.
a 10kO 2W resistor to the anode button.
9. When service is required, observe the original lead dress. ExtraPWB
White line side
precaution should be given to assure correct lead dress in the high
voltage circuit area. Where a short circuit has occurred, those com-
PW
A V
ponents that indicate evidence of overheating should be replaced.
WHT
Always use the manufacturer's replacement components.
No. 517983 |
ACEC
