As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STRONG ELECTRICAL SMELL AND SMOKE IN FORWARD CABIN WHILE ON TAXI OUT. AIRCRAFT RETURNED TO GATE. *S/D* THE LAVATORY FLUSH MOTOR WAS CONTINUOUSLY RUNNING AND OVERHEATED, CAUSED BY A STICKING LAVATORY FLUSH SWITCH. THE FLUSH MOTOR AND TIMER WERE REPLACED. ALL 747-238 AIRCRAFT WERE INSPECTED FOR STICKING SWITCHES AND LUBED, TWO AIRCRAFT HAD STICKING SWITCHES AND WERE REPLACED.