Cameron KS21TK305A, Service Manual

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SERVICE MANUAL
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High Voltage System remove static charges from it by connecting a 10K Ohm resistor in series Wan
insulated wire(such as test probe) between the picture tube dag and 2nd anode lead(Have AC line
cord disconnected from AC supply).
The picture tube use in this receiver employ integral implosion protection. Replace with a tube
of the same type number for continued safety. Do not lift picture tube by the neck. Handle the
picture tube only when wearing shatterproof goggles and after discharging the high voltage
completely, Keep others without shatter proof goggles away.
Before returning the receiver to the user, perform the following safety checks:
1. Inspect all lead dress to make certain that leads are not pinched or that hardware is not
lodged between the chassis and other metal parts in the receiver.
2. Replace all protective devices such as non-metallic control knobs, insulating fish-papers,
cabinet backs, adjustment and compartment covers of shields, isolation resistor-capacitor networks,
mechanical insulators etc.
3. To be sure that not shock hazard exists, a check for the presence of leakage current should be
made at each exposed metal part having a return path to the chassis (antenna, cabinet metal, screw
heads knobs and/or shafts, escutcheon, etc.) in the following manner.
Plug the AC line cord directly into a 110V/240V (or 180V/240V), AC receptacle. (Do not use
an Isolation Transformer during these checks.) All checks must be repeated with the AC line cord
plug connection reversed. (If necessary, a non-polarized adapter plug must be used only for the
purpose of completing these checks.)
If available, measure the current using an accurate leakage current tester. Any reading of
0.35mA or more is excessive and indicates a potential shock hazard which must be corrected before
returning the receiver to owner.
If a reliable leakage current tester is not available, this alternate method of measurement should
be used. Using two clip leads, connect a 1500 Ohm, 10 watt resistor paralleled by a 0.15MF
capacitor in series with a known earth ground, such as a water pipe or conduit and the metal part to
be checked. Use a VTVM or VOM with 1000 Ohms per Volt, or higher, sensitivity to measure this
AC voltage drop across the resistor,. Any reading of 0.35 volt RMS of more is excessive and
indicates potential shock hazard which must be corrected before returning he receiver to the owner.
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