Nautel NX15, Troubleshooting Manual

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NX25/NX15 Troubleshooting Manual Responding to alarms
Page 1-6 Issue 5.0 2016-05-06
Table 1.1: Troubleshooting Alarms
Alarm (with Prefix) Description and Troubleshooting Action
Controller: Audio Loss
Shutdown This alarm occurs if the modulation level is below the preset
threshold for the designated period of time set in the Audio Loss
settings of the current preset, and the desired action was set to
RF Inhibit. This will cause the transmitter to shut down its RF
output until the exciter determines that the modulation source has
returned. If this alarm is unexpected, check the audio inputs
specified in the preset and verify there is signal present.
Controller: Arc Shutback This alarm indicates the transmitter has entered a shutback (see
Shutback on page 3.1.10 of the Operations & Maintenance
Manual for a description of the shutback routine) due to one of the
rack controller’s arc detectors being activated. When this fault
occurs, the transmitter immediately inhibits PDM and the
transmitter's output power drops to 0 W. Once the fault clears the
transmitter will automatically recover, either to the power setpoint,
or to a reduced power as determined by the cutback routine (see
“Cutback:” on page 1-8 of the Operations & Maintenance Manual
for a description of the cutback routine). Visually inspect the inside
of the transmitter to locate the fault causing the arc detector to
trigger.
Controller: Brownout
Reset This alarm is only visible in the transmitter logs, and indicates the
controller was reset because its +5 V power supply voltage was
less than +4.3 V, but remained above +1.4 V, and then
subsequently recovered. This alarm should occur concurrently
with other alarms. Follow the troubleshooting information for the
associated alarms. If the alarm persists without the presence of
other alarms, replace the control/interface PWB
(see “Control/
interface PWB replacement” on page 1-60 ).