As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER PUSH BACK AND ENGINE START BURNING SMELL IN AFT CABIN WITH GALLEY LIGHT FLICKERING. COMPLIED WITH FIM 21-00 TASK 806, PER MM 05-51-56. UNABLE TO DUPLICATE ANY SMELL OF SMOKE OR FUMES. HOWEVER, FOUND CEILING LIGHT AT 20 DEF FLASHING. SUSPECT BALLAST FAILURE. R & R CEILING LIGHT ASSY IAW MM 33-22-00.