INTRODUCTION TO 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 carriers 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
The part that is not operating correctly and is causing the problem.
The problem reported to unit maintenance.
3. VERIFY NO FAULTS
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 carrier to make sure
that you have corrected the reported problem. If troubleshooting does not identify a
faulty part, the carrier is defective beyond the level of unit maintenance.
4. LIGHT BULB CHECK:
In troubleshooting tasks checking indicator lights, light bulb is good if multimeter
indicates any continuity.
A troubleshooting procedure serves as a starting point for your troubleshooting work. You will branch in and out of
procedures as you work to find a fault. Also, you will correct the fault and check that the fault has been corrected. The parts
of a troubleshooting procedure are given below.
This is the name of the procedure.
2 INITIAL SETUP
This tells you the tools, materials/parts, personnel, references, and equipment
conditions needed to do the procedure.
3 TASK STEPS
These boxes give you step-by-step instructions.
These help you locate and identify parts.
This is the last step in YES blocks. The answer to this question will direct you to
the next block.
6 REFERENCE LETTER
This will send you to the correct block to continue with the troubleshooting