As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: RATTLING NOISE ABOVE ROW 26, ACCOMPANIED BY RECIRCULATION FAN STATUS MESSAGE AND ELECTRICAL SMELL. TURNED UPPER RECIRCULATION FANS OFF AND BURNING SMELL DISAPATED AND RATTLING NOISE STOPPED. ***SUPPLEMENTAL INFORMATION: MAINTENANCE INSTALLED SERVICEABLE AFT R/H RECIRC FAN IAW 21-25-01.