Operating instructions

TM 11-5865-229-12
SECTION IV
TROUBLESHOOTING PROCEDURES
SECTION CONTENTS
PAGE
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-5
OPERATIONAL TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
3-8 GENERAL.
Troubleshooting at the AVUM level is limited to procedures that can be performed while the CM Set is installed
in the aircraft. These procedures include:
inspection of BIT indicators
checking cable connections
replacing faulty LRUs
performing the operational test
3-9 OPERATIONAL TEST.
Perform the operational test prior to flying any mission requiring the use of the CM Set, after any LRU
replacement or whenever a problem is observed during CM Set operation. This test is designed to verify the
correct operation of the CM Set LRUs. Always begin with test number 1 (LAMP TEST).
Never begin any test unless you are sure the aircraft is safe for maintenance. Refer to the aircraft
manual for specific instructions and safety precautions.
a. Tools and Materials Required.
b.
Radar Signal Simulator, SM-756/APR-44(V)
Torque Wrench, Preset CHA-5
Wrench, Open End Standard, 9/16"
Flashlight
Cable, TNC-to-TNC
Coaxial Termination, 374BNM
Aircraft Headset (Refer to aircraft manual for type required.)
Test Procedure.
The columns in the test procedure are explained below.
ITEM . . . . . . . . . . . .
This column lists the test number and step letters under that column.
ACTION . . . . . . . . . . . . .
This column tells you what to do to test the CM Set.
NORMAL INDICATION . . . This column specifies the CM Set’s normal indications. If the CM Set
gives the normal indication, it is working properly. G
O on to the next
step.
CORRECTIVE ACTION . . . This column lists the corrective actions you should take if the CM Set
does not give normal indications. Remember, whenever you replace
a part of the CM Set, restart the operational test at test number 1,
step a.
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