As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMELL OF BURNING PLASTIC 10 MINUTES PRIOR TO LANDING. PERFORMED INSPECTION OF ALL AVIONICS COMPARTMENTS NO TROUBLES NOTED. SUSPECT SMELL COMING FROM COCKPIT DOOR LOCKING SYS BUZZER. R & R BUZZER 23MQ OPERATIONS TESTED GOOD, NO TROUBLES NOTED IAW AMM 52-51-13-000-001-A.