CHAPTER 1 GENERAL ADJUSTMENTS
SAFETY INSTRUCTIONS
WARNING: BEFORE SERVICING THIS CHASSIS, READ THE
X-RAY RADIATION PRECAUTION
ADJUSTMENTS
1.Excessive high voltage can produce potentially hazardous
Refer to
(See SETTING & ADJUSTING DATA on page 17)
Each time a receiver requires servicing, the high voltage should be checked following the HIGH VOLTAGE CHECK procedure in this manual. It is recommended that the read- ing of the high voltage be recorded as a part of the service record. It is important to use an accurate and reliable high voltage meter.
2.This receiver is equipped with a Fail Safe (FS) circuit which prevents the receiver from producing an excessively high voltage even if the B+ voltage increases abnormally. Each time the receiver is serviced, the FS circuit must be checked to determine that the circuit is properly functioning, follow- ing the FS CIRCUIT CHECK procedure in this manual.
3.The only source of
4.Some part in this receiver have special
INFORMATIONS GENERAL
SAFETY PRECAUTION
WARNING : Service should not be attempted by anyone unfa- miliar with the necessary precautions on this receiver. The fol- lowing are the necessary precautions to be observed before servicing this chassis.
1.An isolation Transformer should be connected in the power line between the receiver and the AC line before any serv- ice is performed on the receiver.
2.Always discharge the picture tube anode to the CRT con- ductive coating before handling the picture tube. The pic- ture tube is highly evacuated and if broken, glass fragments will be violently expelled. Use shatter proof goggles and keep picture tube away from the unprotected body 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;
4.Before returning the set to the customer, always perform an AC leakage current check on the exposed metallic parts of the cabinet, such as antennas, terminals, screwheads, metal overlays, control shafts etc. to be sure the set is safe to operate without danger of electrical shock. Plug the AC line cord directly into a 120V AC outlet (do not use a line isolation transformer during this check). Use an AC volt- meter having 5000 ohms per volt or more sensitivity in the following manner:
Connect a 1500 ohm 10 watt resistor, paralleled by a 0.15 μF, AC type capacitor, between a known good earth ground (water pipe, conduit, etc.) and the exposed metallic parts, one at a time. Measure the AC voltage across the combi- nation of 1500 ohm resistor and 0.15 μF capacitor. Re- verse the AC plug at the AC outlet and repeat AC voltage measurements for each exposed metallic part. Voltage measured must not exceed 0.3 volts rms.This corresponds to 0.2 milliamp. AC. Any value exceeding this limit consti- tutes a potential shock hazard and must be corrected im- mediately.
AC VOLTMETER
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pipe, conduit, etc. | 1500 ohm | |||||||||
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SPECIFIC
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in this chassis have special
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,
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