Specifications

2. If the switches check normal, use the overall wiring
diagram to trace the interconnecting wires and cables
between the assemblies to find the open circuit.
6.5.2.11 2C3/2C4 Illuminated
a. Ensure that P10 is properly installed.
b. Measure the voltage across F8, it should be 0VDC.
1. If it measures +24VDC, replace the fuse and measure
again. If the fuse opens again, measure the interlock
line resistance using another interlock line as a refer-
ence.
c. Measure the voltage at TP20, it should be +24VDC.
1. If the voltage is +24VDC, refer to the troubleshooting
section for the Frequency Control Interface board.
d. If the voltage is 0VDC, unplug P10 and ohmmeter check
the resistance from P10-8 to P10-15.
1. If the pins are open, visually inspect the jumper on the
plug and the contacts to find the open connection.
6.5.3
Tune Servo Fault/RF Mute
If these front panel LEDs are illuminated RED, this indicates
that the Tune Servo may be out of position.
NOTE
In the Normal Operation mode, the Tune Servo Fault LED is not
illuminated and the Multimeter is turned off. If this fault occurs
the LED will be illuminated RED and the Multimeter will be
automatically turned on.
6.5.3.1 Position Out Of Range
This fault occurs when the Position voltage is more than .5V
from the Reference voltage in either a positive or negative
direction. For example if the servo Reference is set for 2.5 and
the servo Position is 3.0, the fault will occur. If the servo
Reference is 2.5 and the Position is 2.1, the fault will not occur.
Possible reasons why this fault might occur are as follows:
a. Improperly set Reference voltage when in the Frequency
Change mode.
1. Check to make sure the Reference voltage is properly
set using the Transmitter Band Chart.
b. If the peak in power occurs far enough away from the
Reference to cause the fault, it indicates a possible failure
of Bandswitched components 1C1, 2C5, or 2L1.
c. Use the Band Indicator on the Frequency Control Inter-
face board to check for the proper relay drive outputs for
the selected frequency.
WARNING
ENSURE THAT THE TRANSMITTER IS TURNED OFF AND ALL
PRIMARY POWER IS TURNED OFF AT THE WALL DISCONNECT
SWITCH BEFORE OPENING ANY DOOR OR PANEL. BEFORE
REMOVING PANELS OR OPENING DOORS, VERIFY THAT THE
RF AMP POWER SUPPLY IS DISCHARGED BY CHECKING
“PA+VDC” ON THE FRONT PANEL MULTIMETER. USE A VOLT-
METER TO VERIFY THE POWER SUPPLIES HAVE BEEN DIS-
CHARGED PRIOR TO TOUCHING ANY COMPONENTS.
1. If the outputs are correct measure the coil resistance of
the relays, check the Inductor Switch operation, and
visually inspect the components.
2. If the outputs are not correct, refer to the Troubleshoot-
ing section for the Frequency Control Interface board.
6.5.3.2 A/C Power Failure
This fault will occur along with the Load Servo Fault when A/C
power has been removed long enough for the battery backup
supply to depleted. The transmitter will have to be manually
retuned to the selected frequency before normal operation can
resume.
6.5.3.3 Servo Supplies Missing
a. With only the low voltage on, observe the +20VDC DS7
and -20VDC DS9 indicators on the Frequency Control
Interface board.
1. If they are not illuminated GREEN, verify that the
Servo Supply circuit breaker is in the on (up) position
and that F13 and F14 on the Frequency Control Inter-
face board are not open.
2. Troubleshoot the Servo Supply if needed.
b. Observe the +15VDC DS1 and -15VDC DS2 indicators
on the Frequency Control Interface board when the Tune
Raise/Lower switch is activated.
1. If both indicators do not illuminate GREEN for 60
seconds, refer to the Troubleshooting section for the
Frequency Control Interface board.
c. Measure voltages at the Tune Servo Output on TP38.
d. When the servo Raise/Lower is activated, the voltage
should switch between + and - output polarity.
1. If there is no output or no change, refer to the Trou-
bleshooting section for the Frequency Control Inter-
face board.
e. Measure the Position Feedback at J13-1 if the servo is
operational.
f. The voltage should vary from 0 .7VDC to 13VDC as the
servo travels from one mechanical stop to the other.
WARNING
ENSURE THAT THE TRANSMITTER IS TURNED OFF AND ALL
PRIMARY POWER IS TURNED OFF ATTHE WALL DISCONNECT
SWITCH BEFORE OPENING ANY DOOR OR PANEL. BEFORE
REMOVING PANELS OR OPENING DOORS, VERIFY THAT THE
RF AMP POWER SUPPLY IS DISCHARGED BY CHECKING
“PA+VDC” ON THE FRONT PANEL MULTIMETER. USE A VOLT-
METER TO VERIFY THE POWER SUPPLIES HAVE BEEN DIS-
CHARGED PRIOR TO TOUCHING ANY COMPONENTS.
1. If the voltage does not change, visually inspect and
measure the resistance of the position potentiometer on
the assembly.
6-16 888-2339-002
WARNING: Disconnect primary power prior to servicing.