T R O U B L E S H O O T I N G
Section I. HOW TO USE TROUBLESHOOTING
The purpose of unit maintenance level troubleshooting is to diagnose carrier problems which are reported to
unit maintenance. Troubleshooting tasks in this manual are common to all earners except where indicated.
You should not begin unit maintenance troubleshooting until all operator troubleshooting procedures have
been completed. You will perform four actions in unit maintenance troubleshooting:
1. Before starting a troubleshooting task, verify that the reported problem is present in the carrier.
2. After verifying the symptom, find the part that is causing the problem.
3. Replace or adjust that part.
4. Check to make sure the problem no longer exists, and that there are no other problems.
DEFINITIONS AND DESCRIPTIONS OF TROUBLESHOOTING PROCEDURES
Troubleshooting tasks always have a beginning and an end. You will use task steps, test procedures, indexes,
maintenance tasks, and other technical manuals to troubleshoot. Troubleshooting uses the following terms
that are not used in other kinds of tasks:
FAULT: The part that is not operating correctly and is causing the problem.
The problem reported to unit maintenance.
VERIFY NO FAULTS FOUND: After you have completed the corrective action, you must verify
that no faults exist. If the fault condition still exists, then the fault is not fixed or there is another
fault. If this happens, start at the beginning of the troubleshooting procedure until you find and correct
all faults. Always operate the system and/or earner to make sure that you have corrected the reported
problem. If troubleshooting does not identify a faulty part, the earner is defective beyond the level of