What was found
MASTER CAUTION. CHECKED FIRE DETECTOR, APU BOTTLE LOW. EXTINGUISHED MASTER WARNING AND COMPLETED CHECKLIST. BECAME INTERMITTENT WITH MASTER WARNING AND CHIMES SOUNDING UNTIL TOUCHDOWN. ON TOUCHDOWN MASTER WARNING, CHIMES, AND APU BOTTLE LOW LIGHTS EXTINGUISHED AND REMAINED OFF. NO OTHER WARNINGS OR CAUTIONS. COMPLIED WITH FIM TASK 26-23-00-810-802. R & R APU FIRE EXT BOTTLE IAW AMM TASK 26-23-01-000/400-801. PERFORMED OPS TEST OF APU FIRE DETECTION SYS IAW AMM TASK 26-13-00-710-801. SYS TESTED GOOD.