As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMOKE COMING FROM SINK IN THE LAV ELECTRICAL BURNING SMELL. FOUND BOTH POT WATER DRAIN HEATERS WORKING NORMALLY. SUSPECT SINK DRAIN HEATER OR ASSOCIATED WIRING. PULLED AND COLLARED CB E-11. INSPECTED WIRING BEHIND AND UNDER LAV SINK COMPARTMENT AND FOUND SMELL FROM CALL SWITCH CIRCUIT BOARD. REMOVED AND REPLACED LAV ATTEND CALL SWITCH CIRCUIT BOARD. OPS CHECK SAT.