CHAPTER 1 GENERAL ADJUSTMENTS
SAFETY INSTRUCTIONS
WARNING : BEFORE SERVICING THIS CHASSIS, READ THE OX-RAY RADIATION PRECAUTION�, OSAFETY PRECAU-
TION� AND OPRODUCT SAFETY NOTICE� INSTRUCTIONS BELOW.
X-RAY RADIATION PRECAUTION
1. Excessive high voltage can produce potentially hazard-2. This receiver is equipped with a Fail Safe (FS) circuit which
ous X-RAY RADIATION. To avoid such hazards, the highprevents the receiver from producing an excessively high
voltage must not be above the specified limit. The nominalvoltage even if the B+ voltage increases abnormally. Each
value of the high voltage of this receiver is (A) kV at zerotime the receiver is serviced, the FS circuit must be checked
beam current (minimum brightness) under a 120V Ato determine that the circuit is properly functioning, follow-C
power source. The high voltage must not, under aning the FS CIRCUIT CHECK procedure in this manual.y cir-GENERAL ADJUSTMENTS
cumstances, exceed (B) kV.3. The only source of X-RAY RADIATION in this TV receiver
Refer to table-1 for high voltage (A), (B).is the picture tube. For continued X-RAY RADIATION pro-
tection, the replacement tube must be exactly the same
(See SETTING & ADJUSTING DATA on page 17)
type tube as specified in the parts list.
Each time a receiver requires servicing, the high voltage
4. Some part in this receiver have special safety-related char-
should be checked following the HIGH VOLTAGE CHECKacteristics for X-RAY RADIATION protection. For contin-
procedure in this manual. It is recommended that the read-ued safety, parts replacement should be undertaken only
ing of the high voltage be recorded as a part of the service
after referring to the PRODUCT SAFETY NOTICE below.
record. It is important to use an accurate and reliable high
voltage meter.
SAFETY PRECAUTION
WARNING : Service should not be attempted by anyone unfConnect a 1500 ohm 10 wa-att resistor, paralleled by a 0.15
miliar with the necessary precautions on this receivmFer, A. CThe f type capacitorol-, between a known good earth ground
lowing are the necessary precautions to be observed before(water pipe, conduit, etc.) and the exposed metallic parts,SPECIFIC INFORMATIONS
servicing this chassis.one at a time. Measure the AC voltage across the combi-
1. An isolation Transformer should be connected in the ponation of 1500 ohm resistor and 0.15 wermF capacitor. Re-
line between the receiver and the AC line before anverse the Ay serv- C plug at the AC outlet and repeat AC voltage
ice is performed on the receiver.measurements for each exposed metallic part. Voltage
2. Always discharge the picture tube anode to the CRmeasured mT con- ust not exceed 0.3 volts rms. This corresponds
ductive coating before handling the picture tubeto 0.2 milliamp. The pic-. AC. Any value exceeding this limit consti-
ture tube is highly evacuated and if broken, glass frag-tutes a potential shock hazard and must be corrected im-
ments will be violently expelled. Use shatter proof gog-mediately.
gles and keep picture tube away from the unprotected bodyAC VOLTMETER
while handling.
3. When replacing a chassis in the cabinet, always be cer-
tain that all the protective devices are put back in place,
such as; non-metallic control knobs, insulating covers,
shields, isolation resistor-capacitor network etc.
4. Before returning the set to the customer, always perform
an AC leakage current check on the exposed metallic parts0.15mF
of the cabinet, such as antennas, terminals, screwheads,
metal overlays, control shafts etc. to be sure the set isPlace this probe on
safe to operate without danger of electrical shock. PlugGood earth groundeach exposed
the AC line cord directly into a 120V AC outlet (do not usesuch as a watermetallic part.
a line isolation transformer during this check).pipe, conduit, etc. Use an AC
1500 ohm
voltmeter having 5000 ohms per volt or more sensitivity in10 watt
the following manner:
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These characteristics are
often passed unnoticed by a visual inspection and the protection afforded by them cannot necessarily be obtained by using
replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety char-
acteristics are identified in this manual and its supplements; electrical components having such features are identified by
the international hazard symbols on the schematic diagram and the parts list.
Before replacing any of these components, read the parts list in this manual carefully. The use of substitute replacement
parts which do not have the same safety characteristics as specified in the parts list may create shock, fire, X-ray
radiation or other hazards.
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ACEC
