1–9 ROADMAP APPROACH (cont)

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.