Specifications

Section VI
Troubleshooting
6.1 Introduction
This section of the technical manual will contain troubleshooting
procedures for the transmitter.
This troubleshooting section is divided as follows:
a. Troubleshooting Control Front Panel Indicators (Page 6-1)
b. Troubleshooting Frequency Control Front Panel Indica-
tors (Page 6-13)
c. Troubleshooting Power Supply Status Panel Faults (Page 6-18)
d. System Faults With No Front Panel Indication (Page 6-19)
e. Troubleshooting Low Voltage Power Supplies (Page 6-20)
f. Measuring RF Amplifier Drive/Drain Amplitude And
Phase (Page 6-22)
This section is a troubleshooting guide for the transmitter as a
system. The purpose of this section is to isolate the problem to a
board or circuit then the troubleshooting for that board will be
covered in the section of the manual for that particular board.
6.2 Making Safe Measurements
This equipment to be opened, operated, and maintained by
authorized personnel only.
Never work when alone or tired.
Read safety warning and first aid information in the front of this
manual before proceeding.
After the transmitter has been turned off, verify that the RF AMP
PowerSupply is discharged by checking “PA+VDC” on the front
panel multimeter.
Use breakers or disconnect switches to remove all primary power
to transmitter and peripheral equipment before opening enclo-
sures, or removing any panel or shield.
Do
not rely on internal contactors, relays, interlock, or switching
devices to remove all dangerous voltages.
Use a volt-meter to verify the power supplies have been dis-
charged prior to touching any components.
If a voltage reading or waveform analysis is required, route test
leads through an opening in the cabinet to the desired measure-
ment point. Secure leads away from any circuit with voltages
beyond the break down point of their insulation or the insulation
rating of the measurement device.
Do not hold the measuring device in your hand while the equip-
ment is energized. Securely ground the chassis of any scope,
analyzer, or other test equipment.
Do not operate with doors, shields or panels removed.
After taking reading, use breakers or disconnect switches to
again remove all primary power to transmitter and peripheral
equipment before opening enclosure where test leads were
routed or connected. Verify the discharge of all high voltage
points and points where test leads are attached before touching
any points or removing test leads.
6.3 Troubleshooting Control Front Panel
Indicators Faults
The following is a list of all the transmitter faults that appear on
the Control front panel of the transmitter.
RF Flow Indicators
FRQUENCY SYNTHESIZER Page 6-2
BUFFER AMP Page 6-2
PREDRIVER Page 6-3
DRIVER
HIGH DRIVE Page 6-4
LOW DRIVE Page 6-3
RF AMP
FUSE Page 6-5
TEMP Page 6-5
OUTPUT MONITOR
NETWORK VSWR Page 6-6
ANTENNA VSWR Page 6-7
VSWR TEST Page 6-7
SUPPLY FAULT Page 6-8
Digital Audio Flow Indicators
ANALOG INPUT
POWER FOLDBACK Page 6-8
SUPPLY FAULT Page 6-8
A/D CONVERTER
CONVERSION ERROR Page 6-8
SUPPLY FAULT Page 6-8
ENCODERS
MODULE/CABLE INTERLOCK Page 6-8
SUPPLY FAULT Page 6-9
Control and Power Supply Indicators
CONTROLLER
RF MUTE Page 6-12
SUPPLY FAULT Page 6-12
RF AMP POWER SUPPLY
A/C MAINS FAULT Page 6-10
CURRENT FAULT Page 6-10
VOLTAGE FAULT Page 6-11
TEMP FAULT Page 6-11
AIR FLOW
REDUCED Page 6-12
FAULT Page 6-13
INTERLOCKS
DOOR Page 6-11
EXTERNAL Page 6-12
888-2339-002 6-1
WARNING: Disconnect primary power prior to servicing.