Nautel NG1000, Troubleshooting Manual

Page: 32 / 164

NG1000 Troubleshooting Manual Responding to alarms
Page 1-10 Issue 0.4 2010-10-12
Transmitter Generated Faults
TXA (or TXB) AC
Fault TRANSMITTER A
TRANSMITTER B This alarm occurs when an associated transmitter’s
power supply module (U3 or U4) detects a PS Ac Fail,
caused when the input ac voltage is less than 180 V
ac or above 264 V ac. These fault signals are passed
to the system controller on dedicated lines. Check the
ac power source. If it is OK, suspect a fault with the
power supply module (U3 or U4). To replace a power
supply module, see
“Power Supply Module
Replacement” on page 1-17 .
TXA (or TXB) All PAs
Failed TRANSMITTER A
TRANSMITTER B This alarm occurs when all PAs in the transmitter are
indicating PA Fail alarms.
TXA (or TXB) Audio
Shutdown TRANSMITTER A
TRANSMITTER B This alarm occurs during a firmware upgrade. It
indicates that the associated transmitter is not
processing audio because it is undergoing a firmware
upgrade.
TXA (or TXB) Coax
Interlock TRANSMITTER A
TRANSMITTER BD This alarm occurs when the coax interlock input from
the system controller is not in the correct state,
inhibiting the associated transmitter’s output.
TXA (or TXB) Comm
Fail TRANSMITTER A
TRANSMITTER B This alarm occurs when the associated transmitter is
not responding on the serial bus, indicating lack of
power, a faulty cable or a hardware fault. Check the
serial cables between the system controller and the
associated transmitter.
TXA (or TXB) Cutback TRANSMITTER A
TRANSMITTER B This alarm occurs when the associated transmitter has
reduction in RF output power, caused by the
occurrence of multiple shutback events within a pre-
defined time period.
TXA (or TXB) Disch
PA Volts TRANSMITTER A
TRANSMITTER B This alarm occurs when the associated transmitter is
taking longer than expected to discharge the voltage
from the power supply after turning off (maximum
acceptable time is 2 s).
TXA (or TXB) Exc
Rebooted TRANSMITTER A
TRANSMITTER B This alarm occurs when the associated transmitter’s
exciter reboots. Typically this alarm accompanies a
loss of ac power to the transmitter.
Alarm (with Prefix) Alarm/Status LED Description and Troubleshooting Action