As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING D1R EPAS ARM, THE EPAS BATTERY PACK GREENTEST LIGHT NO COME ON REF HAECO NR NO.9484014. REPLACED EPAS 9 VOLT BACK UP BATTERY AND REPLACED EPAS BATTERY PACK, CONDITION CHECK NORMAL, CARRIED OUT EPAS BATTERY OPERATIONAL TEST, TEST NORMAL REF AMM 52-11-20-400-806/805 & AMM 52-11-20-700-803 REV.100.