As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY LIGHTS INOPERATIVE ABOVE 4DF, ROWS 9-13DF. ALSO INOPERATIVE AT DOOR R1 (ALL LIGHTS). RT FWD OVERWING EXIT LIGHT OUTSIDE INOPERATIVE. GROUNDED - YES. SWAPPED COMPLETE POWER SUPPLY IN LIGHTS AT R1 DOOR OPERABLE. SWAPPED UNITS BACK. SUSPECT BATTERY PACK. REPLACED TWO BATTERY PACKS. ALL LIGHTS NOW FUNCTIONAL.