As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AURCRAFT CARRIED OUT AN AIR-RETURN WITH AN APPARENT BURNING SMELL IN THE CABIN. UPON ENGINEERING INVESTIGATION, THE BURNING SMELL WAS TRACED TO THE CABIN LHS NR 2 FLUROESCENT TUBE LAMP HOLDER P/N BV03302-11-150. THE LAMP HOLDER WAS REPLACED AND THE AIRCRAFT RETURNED TO SERVICE. NO FURTHER DEFECT HAS BEEN REPORTED.