NV5/NV3.5 Troubleshooting Manual Responding to alarms
Page 1-14 Issue 3.2 2014-12-10
Controller: Reject A
Power High # (1-8)
This alarm occurs if any of the reject load power samples exceeds its
high reject power threshold (600 W in analog or hybrid mode; 300 W
in all-digital mode). Typically, high reject power is a result of RF power
module failure or removal. If no other alarms are being indicated,
suspect the control/interface PWB.
Controller: Reject
Power Foldback
This alarm occurs if the transmitter’s reject load’s average power
exceeds its reject power foldback threshold (750 W in analog or
hybrid mode; 375 W in all-digital mode). The transmitter’s forward
power will be reduced each time the alarm occurs, until the fault
clears. Typically, high reject power is a result of RF power module
failure or removal. If no other alarms are being indicated, suspect the
control/interface PWB.
Controller: Reject
Power Shutdown
This alarm occurs if the transmitter tries to reduce the forward power
below minimum due to repeated Reject Power Foldback alarms. The
transmitter latches off. See Controller: Reject Power Foldback for
troubleshooting tips.
Controller: Restore
Status CRC Failure
This alarm occurs if the control/interface PWB was unable to maintain
the state of the transmitter through the most recent ac power cycle.
Replace the control/interface PWB’s backup battery (see the Routine
Maintenance section of the Operations and Maintenance Manual). If
battery is OK, cycle ac power (off, then on). If the alarm does not
clear, replace the control/interface PWB.
Controller: SWR
Foldback
This alarm occurs if the transmitter’s average reflected power
exceeds the SWR foldback threshold [198 W (NV5 or NV3.5) for FM
mode, 141 W (NV5 or NV3.5) for FM+HD mode, 57 W (NV5 or NV3.5)
for HD mode) due to a gradual degrading load match. Each time the
SWR foldback threshold is exceeded, the transmitter’s forward power
will be reduced until it reaches minimum power, beyond which the
transmitter will shut down. If the load match improves while the
transmitter is producing RF output, the forward power will increase.
Visually inspect the antenna system for ice buildup and inspect
hardline connections. If no problems are found, suspect the fault
detection circuitry on the control/interface PWB (A1).
Alarm (with Prefix) Description and Troubleshooting Action
To Next Page
Loading...
