As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE, WHILE ACCOMPLISHING ITEM 13 OF TASK CARDS 320K8010 ENO -10 AND 320K8010-ENO 11, FOUND EMERGENCY LIGHTS 51WL AND 53WL INOP IN PASSENGER CABIN (2EA); REF AEROMAN N/R 2020-44247, REMOVED AND REPLACED GPSU BATTERY PACK 11WL IAW AMM 33-51-38 AND PERFORMED OPERATIONAL TEST OF THE EMERGENCY POWER SUPPLY UNITS BY BITE CHECK IAW 33-51-00-710-001-A. TEST IS OK