TM-9-1240-401-34&P Technical Manual for M109 Telescopes and Mounts Download
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6-4 TM 9-1240-401-34&P 6-8. GENERAL SUPPORT SYMPTOM INDEX Troubleshooting Procedure (Page) Mounting surface does not seat M42 periscope correctly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 Windows are broken or cracked . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 Windows are fogged or condensation is present . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 6-9. GENERAL SUPPORT TROUBLESHOOTING MALFUNCTION TEST OR INSPECTION LOCATION CORRECTIVE ACTION 1. MOUNTING SURFACE (1) DOES NOT SEAT M42 PERISCOPE CORRECTLY. Observe visually. a. Clean mounting surface with cleaning compound (item 3, appx B). b. Remove burrs with abrasive cloth (item 4, appx B) dipped in cleaning compound (item 3, appx B). 2. WINDOWS (2) ARE FOGGED OR CONDENSATION IS PRESENT. Observe visually. a. Purge and charge M42 periscope (TM 750-116). b. Repair M42 periscope (ref. para 6-10). 3. WINDOWS (2) ARE BROKEN OR CRACKED. Observe visually. Repair M42 periscope (ref. para 6-10).