As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AIRCRAFT WAS IN HEAVY CHECK MAINTENANCE FOUND THE AFT LAV WASTE BOX DOUBLERS CORRODED. MAINTENANCE REMOVED OLD FASTENERS AND INSTALLED NEW FASTENERS IAW ETD 2012-170-009193 AND SB 190-53-0056. THE AIRCRAFT IS OUT OF SERVICE IN HEAVY CHECK.