As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE F/A REPORTED A LOUD BANG FOLLOWED BY WHITE SMOKE WITH AN ELECTRICAL ODOR NEAR EXIT ROW 19. MAINTENANCE FOUND THAT THE UPPER BEACON POWER SUPPLY HAD OVERHEATED AND THAT THE WIRE HARNESS GOING TO THE BEACON WAS DISCOLORED. THE POWER SUPPLY, WIRE HARNESS, AND UPPER BEACON WERE ALL REPLACED PER AMM. COMPLIED WITH NO GO ODI PREVENTION PROGRAM. ALL CHECKS OKAY.