As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING DESCENT, FLIGHT ATTENDANT HAS REPORTED SPARK COMING OUT OF THE FASTEN SEAT BELT/NO SMOKING SIGN AT ROW 31 DEF. AFTER INVESTIGATION, FOUND THE READING LIGHT POWER UNIT BURNED AT ROW 31 DEF. POWER UNIT WAS DEACTIVATED AND REPLACED AT NEXT MAINTENANCE STATION. DURING INVESTIGATION, FOUND A LOT OF CONDENSATION IN THE CABIN CEILING ABOVE THE POWER UNIT. INSULATION WAS ALSO FOUND WET. PROBLEM IS UNDER REVIEW WITH ENGINEERING AND MFG.