As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - FLIGHT 3980, THE CREW REPORTED PFD#1 FAIL "SMOKED SMELL". THE AIRCRAFT LANDED AT IAH WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED PFD#1, OPERATIONALLY TESTED WITH NO DEFECTS AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.