As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU BOTTLE DISCHARGE LIGHT ON. APU INOP. *S/D* APU FIRE EXTINGUISHER WAS FOUND TO HAVE LOW PRESSURE. REPLACED THE APU FIRE EXTINGUISHER AND RELATED SQUIB PER 757MM 26-22-01. PERFORMED OPERATIONAL CHECK AFTER REPLACEMENT PER SAME 757 MM AND FOUND THAT SYSTEM CHECKED OK.