As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE, EMERGENCY LIGHTS AT LT OVER-WING FAIL TO ILLUMINATE WITH SWITCH IN ARMED AND CIRCUIT BREAKERS H5 & H6 ON THE 49VU OPENED; R & R EPSU & BATTERY PACK IAW AMM 33-51-38 SYSTEM OPS CHECK GOOD IAW AMM 33-51-00-710-804-A.