Nautel XR12, Troubleshooting Manual, Page: 54 / 283

XR12 Troubleshooting Manual Responding to alarms
Page 1-34 Issue 3.0 2009-07-28
5. Repeat Step 3 and Step 4 for the remaining suspect PAs. If any
C
or
G
waveform is not
satisfactory (rectangular wave, 0 to 24 V, assuming 50% duty cycle), the PA associated with
the unsatisfactory waveform is defective and must be replaced (see
“RF amplifier assembly
replacement” on page 1-48 ).
6. Install a repaired or serviceable replacement PA in each vacant PA position, and then restart
the tests at Step 1 .
The following steps list the proper sequence for removing the power module from the transmitter's
test circuit.
7. Remove the jumper that connects TP2 to ground (TP3 or TP4) on the RF drive control
PWB that was installed in “Test cable connection” , Step 8. on page 1-32 . The
Block
(
A
,
B
,
C
and
D
) alarm LEDs will turn on.
8. On the front of the power module under test, press the
INHIBIT
button. The
TEMP/INHIBIT
alarm LED will turn on.
9. Remove the test cable's P3 plug from the power module's J1 connector. J1 is the connector
on the bottom of the power module near the front. Ignore all alarm indications.
10. Remove the test cable's P1 connector from the distribution PWB's J11 connector.
11. Remove the test cable's P4 plug from the power module's J2 connector. J2 is the lower
connector on the rear of the power module.
12. If repairs of the power module are complete, remove the test load from the power module's
J3 connector, and remove the test cable's P2 plug from the transmitter's RF drive splitter's J9
connector
If repairs on the power module are not complete, the test load and the test cable's
connection to the RF drive splitter can remain in place.
WARNING:
The power module must be removed from the transmitter's test circuit
before any sub-assembly is installed or removed from the power
module. Failure to do so can result in damage to the electronic
components in the power module.
It is important to remove the power module from the test circuit by
following Step 7 through Step 12 in the order they are listed to avoid
personal injury and damage to the power module.