TM 1-1520-238-T-4
1–6
1–9
ROADMAP APPROACH (cont)
1–9
c. Each step of the FIP contains a YES/NO question. The answer determines the route to be followed
through the rest of the procedure.
REPAIR REPLACE
OR
TROUBLESHOOT PER SYSTEM MANUAL
PERFORM
MUX READ CODE
PROCEDURE
(IF MUX READ CODE EXISTS)
(TM1-1520-238-T-3)
MOC
FIP
RETURN EQUIPMENT TO SERVICE
START
FAULT
INDICATED
MOC COMPLETED
START
FAILED
COMPONENT
IDENTIFIED
YES/NO
YES/NO
YES/NO
YES/NO
NOTE
IF MUX READ CODE PROCEDURE DOES NOT EXIST
OR DOES NOT ISOLATE THE FAULT, GO TO FIP.
NORMAL
NORMAL
PERFORM FD/LS CHECK
(IF FD/LS CHECK EXISTS)
(TM1-1520-238-T-1)
NORMAL
NORMAL
FAULTY
M58-177
Figure 1–3.
Troubleshooting Flow Diagram
1–10.
FAULT ISOLATION PROCEDURES (FIPs)
1–10
This procedure is used to manually find and correct the fault. FIPs are referenced from MOC results and depend
on the switch control setting of the MOC.
a. Step–by–step checks are done in dichotomous format.
To find and correct faults, start at the beginning and do all the steps in order.
To locate electrical components and connectors, use the ECLC index.
All connectors that have been detached to make checks will be attached prior to continuing to the
next step unless connectors, jacks and relays are specifically called out as being detached or
removed in a FIP step (example: detach P1 or remove relay). When specifically called out, they
will remain detached/removed until the end of the task, unless you are instructed to attach or
install in a later FIP step (example: attach P1 or install relay).
To troubleshoot wiring and circuits, use the wiring interconnect diagrams for that MOC.
b. Checks direct you to the most probable failures.
c. As the procedure is performed, the trouble is found.
d. The checks tell how to correct the trouble.
e. After repair or replacement, the MOC must be repeated.
