As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY CHECK, LAVATORY WASTE BOX INTERNAL DOUBLER IS CORRODED. MX COMPLIED WITH SB R170EO-53-0-0020 FOR WASTE BOX R & R DOUBLERS SEE CONTINUATION CARDS VP-011295-2015/535 FOR WORK DETAILS C1. FCS 53-23-00-001 ACFT REMAINS UNTIL HEAVY CHECK IS COMPLETED.