TM00358 Rev. A
Chapter 5 - LRU Fault Diagnosis
L-3 WESCAM
October 2007
All Rights Reserved
97
5.3
LRU FAULT DIAGNOSIS
Most system failures will be detected by a system or sensor BIT. However, there are some failures that might
prevent the BIT from functioning and assist with determining the failure. In absence of a BIT alarm, operators should
follow the Fault Diagnostic Trees for system power or video failures, and attempt to isolate and resolve the failure
before contact L-3 Wescam for assistance.
The Fault Diagnosis Trees are a guide to find and correct faults. Use them to reduce delays and unnecessary
replacement of system components. It is assumed that the fault is caused by a single failure or malfunction.
The Fault Diagnosis Trees are in a logic-diagram format. Each action is followed by a question with a yes or no
answer. The answer gives either another question or a solution. Do the necessary steps to isolate the cause of the
fault.
Figure 5-3 Fault Diagnostic Tree for Power Loss
Yes
No
Yes
No
Yes
No
Yes
No
Yes
Yes
No
No
No
Light ON
Check Hand
Controller
Power Status
Cycle Power
Check Circuit
Breaker
Breaker
OFF
Restore Breaker
Check Aircraft
power supply
No
+28VDC
Supply
Restore Power
Reinstall
Hand Controller
Cable
Cycle Power
Replace Power
Cable
Cycle Power
Replace Turret
Cycle Power
Contact
L-3 Wescam
Customer Service
Turret Operational
Turret
Powers
Light ON
Check
Continuity of
Turret Power
Cable
Cable
PIN Break
Turret
Powers
Turret
Power
Failure
