Incident Description
While preparing to start the engines, flight attendants in the forward cabin detected a faint odor before closing door 1L. Unable to determine the source, the door was closed for pushback. Shortly after, smoke was discovered near the overhead bin at row 16. The captain was notified and ordered that occupants evacuate if there was a fire onboard.
Evacuation and Door Issues
The jetway was brought back to door 1L. As the smoke dissipated, the flight attendants at doors 1R, 2L, and 2R did not open their doors. However, the flight attendants at the other six doors, unaware of the situation, continued the evacuation. During this process, the ramps at doors 3L and 3R did not inflate, and door 5R jammed halfway open. The ramp packs for doors 3R and 3L were found to be improperly mounted. Additionally, the pack board for door 5R was made for a left-hand door, and its lanyard was not connected to the bottom panel pulley.
Examination Findings
An examination revealed that a ballast for an overhead fluorescent light, part number 69-33C, had overheated and melted its plastic case. This component was identified as the source of the smoke.