As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE, THE LT AFT EMERGENCY LIGHT FAILED TO ILLUMINATE WITH THE SWITCH IN THE ARMED POSITION AND C/B PULLED. REMOVED AND REPLACED THE BATTERY PACK & EPSU 13WL IAW AMM 31-51-38-00-001A, AND 33-51-38-400-001. SYSTEM OPS CHECKED GOOD IAW AMM 33-51-38-710-052B. OPEN