TM-9-1200-215-34&P Technical Manual for M109 Automatic Fire Control System (AFCS) Download
Page 96 of 266
TM 9–1200–215–34&P 3–5 3–10. MANUAL TROUBLESHOOTING PROCEDURES DESCRIPTION This task covers: Manual Troubleshooting INITIAL SETUP Tools: Tool Kits, JTK–17LAL, TK–101/G, or TK–105/G (items 34, 35, & 36, Appendix E) Pin Adapter, Test #16, #20, and #22 (items 4, 5, & 6, Appendix E) Socket Adapter, Test #16, #20, and #22 (items 7, 8, & 9, Appendix E) Electrical Lead (item 14, Appendix E) Equipment Conditions: Appropriate cable assembly removed; if not, remove appropriate cable assembly in accordance with procedure in paragraphs 3–17 or 3–18 as required. Personnel Required: One MOS 35Y NOTE • The following troubleshooting procedures consist of wiring diagrams locating box edge connector pins to internal harness connector terminations. Continuity checks using these diagrams are intended to be used when replacement of internal components fails to correct an Electronic Shop, Transportable, AN/TSM–191(V)3, indicated fault. All other internal troubleshooting will be performed by automated testing. Refer to TPS 12958912 for specific DU troubleshooting procedures. • The continuity check is performed to test for the existence of a connection between two contacts on the cable. The two probes from an ohmmeter are touched to the appropriate pair of contacts and the ohmmeter is monitored. Low resistance readings (approaching 0 ohms) show a good connection; high resistance readings (approaching infinity) show degraded or broken connection. Figure 3–2 shows what contacts the probes should be placed on to check for continuity on the DU–Keyboard cable assembly. Figure 3–3 shows what contacts the probes should be placed on to check for continuity on the DU–Serial cable assembly. MANUAL TROUBLESHOOTING 1. Check for continuity using figures 3–2 and 3–3. 11 10 9 8 7 3 2 1 21 20 1 6 5 2 4 9 3 7 8 13 A1P3 A2P1 Figure 3–2. DU–Keyboard Cable Assembly