As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STIFFENER ON AFT PRESS BULKHEAD JUST O/B OF APU BLEED DUCT HAS OVERHEAT DAMAGE FROM FLOOR LEVEL DOWN TO Y-CORD. REMOVED STIFFENER FROM AFT PRESSURE BULKHEAD JUST OUTBOARD OF APU BLEED DUCT AND INSTALLED NEW STIFFENER PER 13-737-300 SRM 51-40-02.