As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT SERVICE DOOR WILL NOT OPEN FROM THE INSIDE. REMOVED FROM SERVICE. FOUND OUTER HANDLE FLAP COVER JAMMED AGAINST OUTER HANDLE. UNJAMMED OUTER HANDLE FLAP COVER. OPENED AND CLOSED AFT SERVICE DOOR NUMEROUS TIMES FROM THE INSIDE WITH NO ISSUES. PERFORMED OPS TEST OF AFT SERVICE DOOR IAW Q400 AMM 52-41-00-710-*801. OPS TEST PASS. NO FURTHER DEFECTS NOTED AT THIS TIME. AIRCRAFT RETURNED TO SERVICE.