As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN AVIONICS BAY FS 349.00 LOWER FRAME CORRODED BETWEEN STR 26L AND STR 25R. C-CHECK RO 10/9/2020. REMOVED AND REPLACED MAIN AVIONICS BAY FS 349.00 LOWER FRAME BETWEEN STGR 23L-STGR 24R, REF CRJ900 SRM AND DWG. PERFORMED PRESSURE LEAK CHECK, REF CRJ900 AMM NO DEFECTS NOTED. SEE CONTINUE CARD FOR WORK PERFORMED. COMPLIED WITH TASK CARD.