Broadcast Electronics AM-2.5E, User Manual

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2-1
WARNING: DISCONNECT POWER PRIOR TO SERVICING
SECTION II
POWER SUPPLY CIRCUIT BOARD MAINTENANCE
2-1.
INTRODUCTION.
2-2. This section provides maintenance information for the AM-2.5E/AM-5E transmitter
power supply circuit board assembly.
2-3.
SAFETY CONSIDERATIONS.
WARNING
WARNING
WARNING
WARNING
THE TRANSMITTER CONTAINS MULTIPLE CIRCUIT
GROUNDS WITH HIGH AC AND DC POTENTIALS
WITH RESPECT TO THE CABINET WHICH IS AT
EARTH POTENTIAL. DO NOT ENERGIZE THE
TRANSMITTER WITH TEST EQUIPMENT CON
NECTED TO THE TRANSMITTER OUTPUT
NETWORK, RF POWER MODULE, RF COMBINER, OR
POWER SUPPLY COMPONENTS.
2-4. The AM-2.5E/AM-5E transmitters contain high voltages and currents. If safety
precautions are not practiced, contact with the high voltages and currents could cause
serious injury or death. The transmitter is equipped with many built-in safety features,
however good judgement, care, and common sense must be practiced to prevent accidents.
2-5. In addition to high voltages and currents, the transmitters contain multiple circuit
grounds with high ac and dc potentials with respect to the cabinet which is at earth
potential. The potentials could cause serious injury or death if maintenance personnel
simultaneously touch a circuit ground and the cabinet. As a result, operation of the
transmitter with test equipment connected to transmitter output network, RF power
module, RF combiner, or power supply components is extremely dangerous and must not
be attempted. Therefore, never energize the transmitter with test equipment connected
to the transmitter output network, RF power module, RF combiner, or power supply
components. Test equipment may be connected to the ECU circuit boards from the front
of the transmitter using the supplied extender circuit board with power energized. The
maintenance procedures presented in this section should be performed only by trained
and experienced maintenance personnel.
2-6.
FIRST LEVEL MAINTENANCE.
2-7. First level maintenance consists of precautionary procedures applied to the equipment to
prevent future failures. The procedures are performed on a regular basis and the results
recorded in a performance log.
2-8.
CLEANING AND INSPECTION.