As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING T/C 78233001 EMERGENCY BATTERY PACK CAPACITY FUNCTIONAL CHECK FOUND EXTERIOR LIGHTS ON LEFT HAND WING EMERGENCY EXIT DOORS WENT OUT. L1 ENTRY DOOR LIGHT WENT OUT. INTERIOR LEFT ROW FROM SEATS 19-23 WENT OUT OVERHEAD. GROUNDED - YES. REPLACED THE BATTERY PACKS / POWER SUPPLIES M1675 (FWD ENTRY), M1670 (OVERWING AND ROWS 19-23), AND M2627 (RH ROWS 19-23 WERE ALSO OUT EARLY) PER AMM 33-51-06. ALL TESTS NOW NORMAL.