TM 1-1500-204-23-4 (2) Replacement.    Instruments  (indicators  or transmitters)  will  be  removed  and  replaced  for  any  of the following reasons: · Failure    to    indicate    (excluding system failures) · Inaccurate  indicators  (excluding system failure) · Damage case · Loose or distorted pointers · Cracked or loose cover glass · Cracked    or    broken    mounting lugs · Damaged lamp receptacles · Defective setting or caging mechanisms · Defective binding posts · Defective connecting nipples and AN/MS connectors · Dull   or   discolored   luminous   or fluorescent markings · Electrical connectors for bent or damaged pins, stripped, crossed    or    excessively    worn threads, or visual damage to the shell 4-31/(4-32 blank)