As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RTFL DUE TO CREW REPORT OF SMOKE IN THE CABIN. [SUP 05-04-07] SOURCE OF SMOKE WAS TRACED BACK TO A DEFECTIVE COFFEEMAKER IN THE AFT GALLEY. IT WAS DETERMINED THAT A FAULTY HEATER POWER RELAY CONTINUED TO SUPPLY POWER TO THE TANK HEATER ELEMENTS EVEN THOUGH THE CONTROL CIRCUITRY COMMANDED THE HEATERS TO BE TURNED OFF. PRIOR TO THE TRIPPING OF A SAFETY THERMOSTAT, THE SMOKE POINT OF THE POTTING COMPOUND ENCASING THE WIRING WAS EXCEEDED CAUSING SMOKE TO BE RELEASED INTO THE CABIN.