As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOUD KNOCKING FROM F/O SIDE OF A/C ABOVE FL200 ABOVE 250KTS FOUND GRND POWER CONNECTION DOOR OPEN ON ARRIVAL NO DAMAGE TO DOOR FLT CREW STATES SMOOTH LANDING. REF AMM 05-51-01/201. NO FURTHER INSPECTION REQUIRED. DID PRECAUTIONARY WALK AROUND ALONG WITH FO. ALL GOOD.