As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING THE EMERGENCY LIGHT POWER UNIT FUNCTIONAL TEST, THE AFT RT ELPU FAILED TO KEEP THE EMERGENCY LIGHTS ON FOR THE REQUIRED 15 MINUTES WITH A FAULT CODE OF 33500004UT1. R & R AFT RT ELPU IAW AMM 33-50-01. OPS CHECKED GOOD.