As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 4574 DURING CRUISE CREW ADVISES NOTICEABLE BURNING SMELL IN COCKPIT. ACFT REMOVED FROM SERVICE. C/A PERFORMED VISUAL INSPECTION OF CABIN BALLASTS, CABIN LIGHTS, CONTROL MODULE. NO DEFECTS NOTED. NO BURNING SMELL NOTED AT THIS TIME. ACFT RETURNED TO SERVICE.