As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
REMOVE SEAL RETAINER AFT P/N: CC670-38662-5 OF MAIN AVIONICS COMPARTMENT DOOR TO BE INSTALLED ON A/C 921 THEN INSTALL SERVICEABLE PART. NEW SEAL RETAINER AFT P/N: CC670-38662-5S OF MAIN AVIONICS WAS INSTALLED PER CRJ-900 SRM 51-42-06-001-001-A01