Nautel V10, Руководство пользователя по установке и эксплуатации

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V10/V7.5/V5/V3.5 Installation and Operation Manual
Page 5-15
Section 5 System Level Troubleshooting Issue 3.5
5.5.2.5.3 PA Failure
The dc input current for the suspect PA
(A1 - A4) has fallen below a pre-set
threshold. This may be caused by a
cabling fault on the PA, loss of PA voltage
or bias, or a defective FET. The
transmitter output power will be reduced.
The RF power module’s interface PWB
(A5) has four LEDs on its front edge that
represent A1 - A4 (left to right), and will be
red when a PA failure (less than 50% of
the average of the four PA currents) is
detected. Use these LEDs to isolate which
PA has failed on which RF power module.
Troubleshoot as follows:
NOTE
For an IPA PA failure, refer to the
associated IPA fault’s troubleshooting
paragraph (5.5.2.1 - 5.5.2.4).
•
In the main screen, in order to confirm
that it is a true PA failure (fault detection
circuitry test), monitor the applicable
reject load temperature and power
parameters for variations from their
normal values. If these values have not
changed, the power module interface
PWB’s PA failure detection circuitry
may be defective. Refer to the Repair
Manual for further troubleshooting
information. If the values have changed,
it is a true failure. Continue with system
level troubleshooting.
NOTE
A single PA failure will cause another PA
in the same RF power module to be
inhibited. Check the Module Status
screen to determine which PA has failed
(flashes FAIL) and which PA is disabled
(flashes DSBL).
Use the Repair Manual to isolate faults in
the power module interface PWB's PA
failure detection circuitry,
•
Switch the applicable switching power
supply to
STANDBY (toggle down).
The amber PA VOLTS LED on the
front of the RF power module should
turn off. Pull the suspect module
forward and remove it from the cabinet.
Visually inspect the suspect PA’s
output coaxial cable blind-mate
connectors for damage.
•
Check cables between the RF power
module and reject load assembly (A39
or A40, as applicable) inputs for loose
connections or damage. Check cables
between the reject load assembly
outputs and the combiner/filter inputs
[A41A1 - A41A4 for V10/V7.5 or A41A1
and A41A2 for V5/V3.5] for loose
connections or damage.
•
If all cables and connections are
secure, replace the suspect module
with a functional module and verify the
fault is cleared. See the Repair Manual
for further troubleshooting information.
5.5.2.5.4 Fan Failure
The RF power or IPA module’s fan is not
spinning fast enough to exceed the RPM
threshold. This threshold has been
determined to provide acceptable module
cooling. This fault may be paired with a
High Module Temperature fault.
NOTE
When testing for voltage on fan
connectors, the transmitter’s RF power
stage must be enabled (RF On).
(a) Check the fan for blockage. If the fan is
functioning properly (as compared to
the other fans), but the indicated fan
speed is zero, there may be a problem
with the fan’s tachometer circuitry or
the detection circuitry on the applicable
module’s interface PWB (A5).
(b) Measure voltage between pin 1 (+) and
pin 3 (-) of the suspect fan’s connector
(B#P1) while it is connected to the
applicable interconnect PWB.
•
If the voltage is between 47 V and 53 V,
the fan is probably defective and should
be replaced (see 5.6).