As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY EXIT LIGHTS DID NOT COME ON IN ARM POSITION WHEN GND POWER FAILED. REPLACED LT MID POWER SUPPLY & BATTERY, AFT POWER SUPPLY & BATTERY IAW MM33-51-38-4 01. EMER LIGHTS TESTED OK ON FWD ATTN PANEL & ON EACH POWER PACK. ALL EMER LIGHTS ILLUMINATED IN CABIN WITH POWER OFF IN ARM POSITION.