As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) MFG WAS MADE AWARE OF THIS EVENT ON DEC 20, 2012 SHORTLY AFTER THE BEGINNING OF THE BOARDING CA2 REPORTED SMOKE DEVELOPEMENT IN THE AFT CABIN. THE BOARDING WAS STOPPED AND THE PASSENGERS WERE SENT BACK. THE FOLLOWING FLIGHT WAS CONDUCTED WITH ANOTHER ACFT. THE TECHS FOUND BURN MARKS ON THE SLAT FLAP ELECTRONIC CONTROL UNIT NR 1. THE ODOR ORIGINATED FROM SFECU NR 1. THE SFECU NR 1 WAS R & R.