As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BURNING RUBBER SMELL IN FWD CABIN AREA FOLLOWED APPROX 30 SECONDS LATER WITH A RECIRC FAN STATUS MESSAGE. CHECKED MX INFO DISPLAY AND SHOWED FWD UPPER RECIRC FAN OFF. SMELL CLEARED IN LESS THAN ONE MINUTE. ATL MX ASKED THAT THE UPPER RECIRC SWITCH TO BE TURNED OFF. NO FURTHER INDICATIONS. REPLACED FAN CKS GOOD. REINSTALLED CEILING PANELS, REMOVED MCO PLAC P/N 4100945A.