Nautel NV5, Troubleshooting Manual

Page: 35 / 228

NV5/NV3.5 Troubleshooting Manual Responding to alarms
Issue 3.2 2014-12-10 Page 1-27
Attempt to reset an RF power module by pressing Reset on the AUI screen. If you cannot reset the
front panel LED alarm, see
“RF power module troubleshooting” .
RF power module troubleshooting
Refer to “Operating with defective or missing RF power modules” on page 1-27 for removal and
installation instructions and then refer to “Troubleshooting RF power modules” on page 1-33 for
detailed troubleshooting information.
If you have purchased the RF power module extension test jig (Nautel Part # 206-5350), you can use
it to test and troubleshoot RF power modules before returning them to service. Refer to
“Using the
RF power module extension test jig” on page 1-31 for more information.
Operating with defective or missing RF power modules
It is permissible to operate the transmitter with multiple defective or missing RF power module(s).
Table 1.3 on page 1-28 contain the approximate percentage of remaining output power (relative to
original) when power amplifiers (PAs) or RF power modules fail or are removed.
• If an RF power module has one or more defective PAs, as indicated by the AUI's RF Mod-
ules Status screen (and suspect RF power module's front panel LEDs), but is still contribut-
ing to the transmitter's RF output, it may be left on. The transmitter will take necessary
precautions to reduce the stress on components due to the failure, i.e., power reduction.
• If an RF power module must be removed, turn it off prior to disengaging its blind-mating
connectors. Refer to
“Removing and reinstalling RF power modules” on page 1-29 to disable
a module with the transmitter on air. At all other times, turn off the switching power supplies
by pressing the
RF Off
button, then switch off the ac power source at the service entrance.
NOTE:
A defective RF power module can be removed for repair, without turning off the transmitter, as
described in
“Removing an RF power module” on page 1-29 . The transmitter can be operated
at a reduced output power level with an RF power module removed.
CAUTION:
Do not attempt to compensate for power reduction caused by an RF power
module failure by adjusting the RF power level.
NOTE:
There are many possible combinations of PA/module failures or extractions. The best and
worst case situations are shown in
Table 1.3 .