As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE, (REF: NR# 440562-34367) EMERGENCY LIGHTS TEST FAILS, FWD LT BATTERY PACK AND FT LT BATTERY PACK; REMOVED TWO BATTERY PACKS, 10WL AND 13WL IAW AMM 33-51-38-000-002-A. REPLACED TWO BATTERY PACKS 10WL AND 13WL IAW AMM 33-51-38-400-002-A. OPS CHECK GOOD IAW AMM 33-51-38-710-052-B.