As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING TASK CARD 335003 FOR OPS TEST OF EMERGENCY LIGHT SYSTEM, NOTED BATTERY PACK 23LN TRIGGERED FAULT LIGHTS. REMOVED AND REPLACED EMERGENCY LIGHT POWER SUPPLY AT POSITION 23LN IAW AMM 33-50-10-04-01. ALL CHECKS GOOD. P/N 3301-51, S/N ON 2035, S/N OFF 1423.