Specifications

c. If DS2 is illuminated RED, check to make sure that the
captive hardware is securely fastening all five rear doors
to the cabinet.
d. If DS2 is still illuminated:
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.
e. Open the rear door of the Output Network cabinet and
ensure that both grounding sticks are properly inserted
into their holders.
f. If the doors appear to be closing properly and the ground
stick switches are closed, then measure the voltage at the
cathode of CR7 on the Transmitter Interface.
1. If the transmitter is in the Standby mode, this voltage
should be near +12VDC.
2. If the transmitter is in the Normal mode, this voltage
should be +22VDC.
3. If no voltage is present, refer to troubleshooting the low
voltage power supplies, in this section.
g. Check the input to U24-18 on the Controller. If this is a
logic high then refer to the Controller section of the
Manual for troubleshooting.
Note
It is possible, although unlikely, that one of the interlock
switches is defective, or that there is an open in one of the inter-
connecting wires.
6.4.25 External Interlock
If the transmitter has shut itself off and the above LED is
illuminated RED on the Control front panel, the external inter-
lock is open.
a. Measure the resistance of the wires connecting to J6-10
and J6-11 on the External Interface.
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.
b. If the resistance measurement is open, check all devices
connected to these terminals, (phaser door interlock,
dummy load, etc.) to make sure that the device is provid-
ing closed contacts in the normal operating condition.
c. If the resistance measurement is 0 Ohms, measure the
voltage at the cathode of CR37 on the External Interface.
1. This voltage should be +12VDC if the transmitter is in
the Standby mode and +22VDC in the Normal mode.
2. If no voltage is present, verify that the combiner inter-
lock, P29, on the External Interface is in the correct
position.
3. If no voltage is present, troubleshoot the low voltage
supplies.
d. Check the input of U24 on the Controller. If this is a logic
high, refer to the Controller Section for troubleshooting.
6.4.26
Controller RF Mute
If the transmitter is operating at 0W output and the above LED
is illuminated RED on the Control front panel, the transmitter
is responding to another fault by applying an RF MUTE or a
control input has been activated. Check that an external RF Mute
or S1 on the controller is not in the Mute position.
If no other indicators are lit refer to the Controller Section of the
Manual for troubleshooting the Controller.
6.4.27
Controller Supply Fault
If above LED is illuminated RED on the Control front panel,
then one of the power supplies on this board has failed. With
the low voltage on, measure the following voltages on the
Controller.
a. If P53 on the Controller is jumpered 2-3, TP21 should
measure +12VDC.
b. If P53 is jumpered 1-2, TP22 should measure +10VDC.
c. If any one of these supplies is not present, troubleshoot
the low voltage power supplies.
d. If all of these supplies are present, refer to the Trou-
bleshooting portion of Section M, Controller board.
6.4.28
Air Flow Reduced
If the transmitter is operating at a reduced power level, and the
above LED along with the ANALOG INPUT POWER FOLD-
BACK is illuminated RED on the Control front panel, then air
cooling for the transmitter is reduced.
To determine which cabinet(s) have reduced airflow, open all
front doors and observe DS7 on all Modulation Encoders and
DS1 on the Output Monitor.
a. Modulation Encoder A28 monitors the Left PA Cabinet
b. Modulation Encoder A26 monitors the Center PA Cabinet
c. Modulation Encoder A25 monitors the Right PA Cabinet
d. The Output Monitor Board monitors the Output Network
Cabinet
If any of these LEDs is illuminated RED, perform the following
checks for that cabinet.
a. Measure the ambient intake air, it should be less than 50
degrees C.
b. Inspect the air filters, if they are clogged with dirt or sand
they will reduce air flow.
6-12 888-2339-002
WARNING: Disconnect primary power prior to servicing.