Cameron KS21TK305A, Service Manual

Page: 3 / 68

SERVICE MANUAL
3
IMPORTANT SERVICE SAFETY INFORMATION
Operating the receiver outside of its cabinet or with its back removed involves a shock hazard.
Work on these models should only be performed by those who are thoroughly familiar with
precautions necessary when working on high voltage equipment.
Exercise care when servicing this chassis with power applied. Many B plus and high voltage
RF terminals are exposed which, if carelessly contacted, can cause serious shock or result in damage
to the chassis. Maintain interconnecting ground lead connections between chassis, escutcheon,
picture tube dag and tuner when operating chassis.
These receivers have a
“
polarized
”
AC line cord. The AC plug is designed to fit into standard
AC outlets in one direction only. The wide blade connects to the
“
ground side
”
and the narrow blade
connects to the hot
“
side
”
of the AC line. This assures that the TV receiver is properly grounded to
the house wiring. If an extension cord must be used, make sure it is of the
“
polarized
”
type.
Since the chassis of this receive is connected to one side of the AC supply during operation,
service should not be attempted by anyone not familiar with the precautions necessary when
working on these types of equipment.
When it is necessary to make measurements or tests with AC power applied to the receiver
chassis, an Isolation Transformer must be used as a safety precaution and to prevent possible
damage to transistors. The Isolation Transformer should be connected between the TV line cord
plug and the AC power outlet.
Certain High voltage (HV) maybe cause X-ray radiation. Receivers should not be operated with
HV levels exceeding the specified rating for their chassis type. Higher voltage may also increase the
possibility of failure in the HV supply.
It is important to maintain specified values of all components in the horizontal and high voltage
circuits and anywhere else in the receive that could cause a rise in high voltage, or operating supply
voltages. No changes should be made the original design of the receiver.
Components shown in the shaded areas on the schematic diagram and/or identified by in the
replacement parts list should be replaced only with exact factory recommended replacement parts.
The use of unauthorized substitute parts man creats may create shock, fire, X-ray radiation, or other
hazards.
To determine the presence of high voltage, use an accurate high impedance HV meter
connected between the second anode lead and he CRT dag grounding device. When servicing the
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