As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TECH SERVICES REQUESTS FOLLOW-UP TO RECENT HISTORY OF APU FIRE/OH DETECT INOPERATIVE LIGHT ON INTERMITTENTLY. ACFT GROUNDED. WHILE CHECKING DETECTOR TERMINALS, FOUND TAIL PIPE DETECTOR TERMINAL POST BROKEN. R & R TAIL PIPE DETECTOR. OPS CK GOOD. REF AMM 26-15-01, IPC 26-15-01-04.