As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AC WAS IN FOR HEAVY CHECK FOUND CENTER FUSELAGE 3 PAX CABIN FLOOR STRUCTURE SUPPORT UNDER RT SHEAR PANEL BTW FR 87-88 AND RBL 32" AREA. MX REMOVED AND REPLACED RT SHEAR PANEL PN 170-86131-001 IAW SRM 51-42-01. FOR DETAILS OF WORK PERFORMED SEE NRC 4000319-2000-0051. AC RETURNED TO SERVICE.