TM 5-5420-226-20-1 DETAILED TROUBLESHOOTING PROCEDURE Symptom-52 SUPPORT SYSTEM   -  FIRE   EXTINGUISHERS FIXED    FIRE   EXTINGUISHER FAILS   TO   OPERATE WHEN    FIRE   PULL   HARD HANDLE IS  PULLED -No., This procedure  Isto be performed  by two   persons.   The   lead   person    Is referred to as the first technician and shall direct the activity of  the   second person    called   the   second    technician. I Two   different control valves have been  used    on   the   fire    extinguisher. Although different in appearance check out   is  identical. INTERIOR RELEASE MECHANISM -\/ Check interior release mechanism for   binding in first   shot    cycle. I First  Technician   (Operator’s   Station) l    Remove interior release mechanism (page    20-24), l    Arm    release    mechanism if  not    armed for   first    shot, by   pulling FIRE PULL HARD handle all   the    way out,    holding paw!    down and    pushing handle all   the way   in. l    Pull    interior FIRE PULL HARD handle and observe action of   interior release mechanism, paw] should go   into    the   vertical position. Hold second shot    lever    to   make sure    it   does    not    move. l    Push    FIRE PULL HARD handle in   all   the   way. / Did  first  shot  mechanism  work  freely  without binding? \ 1 lNTERIOti 13ELEASE MECHANISM PAWL (SHOWN IN   ARMED POSITION) Repair  interior  release mechanism  (page  20-29). TA107243 (4-554.31 blank)/4-554.32 Change  1