Specifications

c. Verify the blowers are operational and that no blades are
loose.
d. Check that the exhaust airflow is not obstructed creating
excessive back pressure in the cabinet(s).
6.4.29
Air Flow Fault
If the transmitter has shut itself off and the above LED is
illuminated RED on the Control front panel, air flow has been
reduced enough to turn off the transmitter.
Refer to the above AIR FLOW REDUCED section to determine
the problem.
6.5 Troubleshooting Frequency Control
Panel Faults
NOTE
All faults of this type will cause an RF Mute to be applied to the
transmitter
6.5.1 Frequency Synthesizer/RF Mute
If these front panel LEDs are illuminated RED, this indicates
that the selected frequency is out of range.
6.5.1.1 Incorrect Frequency Switch Outputs
Check the 4-4 bit BCD input to the Synthesizer Interface Board.
a. Select F1 on the front panel.
b. Measure the logic level inputs to the Synthesizer Interface
on J6. They should be as follows:
Input Logic Level
MSD1 0
MSD2 0
MSD4 0
MSD8 0
2MSD1 1
2MSD2 0
2MSD4 1
2MSD8 0
3MSD1 0
3MSD2 0
3MSD4 0
3MSD8 1
LSD1 1
LSD2 0
LSD4 1
LSD8 0
c. If the inputs are incorrect, check the 3F Control Board.
d. If the inputs are correct, refer to the troubleshooting
section for the Synthesizer Interface board.
6.5.2
Bandswitch Fault/RF Mute
If these front panel LEDs are illuminated RED, this indicates a
loss of +24VDC or an open interconnect cable in one of the
Bandswitched circuits.
Figure 6-2. Frequency Control Front Panel
888-2339-002 6-13
WARNING: Disconnect primary power prior to servicing.