As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LHR - FLT 136 - EN ROUTE LAX-LHR, DURING CRUISE, FIRST CLASS OVERHEAD PROJECTOR BEGAN MAKING A LOUD POPPING SOUND AFTER WORKING FINE FOR 20 MINUTES. FLASHES OF LIGHT WERE SEEN IN HOUSING. FLIGHT ATTENDANTS REPORTED AN ODOR. POWER SUPPLY WAS REMOVED. LANDED LHR WITHOUT INCIDENT. FIRST CLASS PROJECTOR REPLACED BY RCI. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)