As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ACCOMPLISHEMENT OF TC 78233001 EMERGENCY LIGHT BATTERY PACK FAILED TIME CHECK. ACFT GROUNDED. REMOVED BATTERY PACK POWER SUPPLY AT POSITION M1673 IAW 33-51-06-960-806. INSTALLED BATTERY PACK POWER SUPPLY IAW SAME MM. OPS CHECKED IAW T/C 78233001. OPS CHECKED GOOD.