As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 3712 SMOKE WAS OBSERVED COMING FROM THE NOSE CLAM SHELL DOORS. (WHEN DISCOVERED-UNKNOWN) THE CAPTAIN ELECTED TO RETURN TO ORD. REMOVED AND REPLACED THE NUMBER 1 TRANSFORMER RECTIFIER UNIT IAW CRJ 700 AMM 24-31-01. THE OPERATIONAL CHECK WAS GOOD NO SMOKE NOTED P/N OFF TRU3502 S/N OFF 3522 P/N ON TRU 3502 S/NON 1590. THE AIRCRAFT WAS RETURNED TO SERVICE.