What was found
THE ACFT WAS ENROUTE. A PASSENGER SEATED IN SEAT 6D REPORTED SMELLED SMOKE. THE F/A ALSO NOTICED THE SMOKE ODOR WHICH DISSIPATED QUICKLY. A SHORT WHILE LATER THE FLIGHT CREW ALSO SMELLED THE SMOKE SMELL BUT IT DISSIPATED WITHIN 2 MINUTES. THE FLIGHT LANDED UNEVENTFULLY . MX WAS CALLED TO THE ACFT AND FOUND 1 OF THE OVERHEAD CEILING LIGHTS AT ROW 4, FAILED. THE LIGHT BULB WAS REMOVED AND THE LIGHT BALLAST DISCONNECTED AND THE LIGHT WAS DEFERRED UNDER THE MEL 33-2. WHEN THE ACFT REACHED A MX BASE THE LIGHT BALLAST AND BULB WERE REPLACED. THE LIGHT BALLAST THAT FAILED WAS A PRE-MOD BALLAST, PN BA08006-1, MFG IN 9504 . THESE LIGHT BALLASTS ARE NO LONGER USED IAW AD CF-2004-26R1 AND ARE BEING REPLACED ON AN ATTRITION BASIS. ACFT TSN 48774, CSN 48485.