As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MCN - MAJOR REPAIR - DURING C-19 CHECK CORROSION WAS FOUND ON FLOORBEAM UPPER CHORD AT BS 312 BETWEEN LBL 8 AND RBL 8, WL 208. MAINTENANCE CUTOUT DAMAGED SECTION OF FLOORBEAM UPPER CHORD AT BS 312 FROM LBL 20 TO RBL 21; FABRICATED A NEW REPLACEMENT SECTION OF UPPER CHORD AND 2 EACH REPAIR ANGLES; INSTALLED REPAIR PARTS IAW B737-300 SRM 53-10-51, FIG 205.