Nautel NX15, Troubleshooting Manual

Page: 35 / 274

NX25/NX15 Troubleshooting Manual Responding to alarms
Issue 5.0 2016-05-06 Page 1-27
Module #: High RF Drive This alarm indicates the RF drive duty cycle as measured by the
RF power module is above 65%. The affected RF power module
is immediately disabled. Try swapping the affected RF power
module with an operational RF power module in another position.
If the fault follows the RF power module, replace the RF power
module (see
“Removing an RF power module” on page 1-45 ). If
the fault remains with that position, and is also present on an
adjacent power module, try replacing the associated RF Drive
cable. If the alarm persists, replace the RF Drive Distribution PWB
(see “RF drive distribution PWB replacement” on page 1-63 ) .
Module #: High
Temperature This alarm indicates the power module's measured heatsink
temperature has exceeded 90 degrees Celsius. The affected RF
power module is immediately disabled. If this alarm occurs with
another alarm, troubleshoot that alarm first. Otherwise, see
“Troubleshooting RF power modules” on page 1-48 to determine
whether to replace the affected RF power module or to repair
damaged parts.
Module #: Invalid
Thermistor Sample This alarm indicates there is a problem with the associated RF
power module's temperature sample. When this alarm occurs, the
associated RF power module will disable itself until the condition
is cleared. Inspect R1 on the RF power module, which is soldered
to pads G and H of A1, and repair or replace as necessary.
Otherwise replace the entire RF power module (see
“Removing
an RF power module” on page 1-45 ).
Module #: Low B+
Voltage This alarm indicates the B+ level of the associated RF power
module is below 75% of its nominal value. If the Rack Interface’s
Low B+ Voltage alarm is present, follow the troubleshooting action
for that alarm.
Otherwise, try swapping the affected RF power
module with an operational RF power module in another position.
If that fault follows the RF power module, replace the RF power
module
(see “Removing an RF power module” on page 1-45 ). If
the fault remains with that position, check the B+ fuse associated
with the RF power module and replace as necessary (see
“Module #: Low B+ voltage” on page 1-43 ).
Alarm (with Prefix) Description and Troubleshooting Action