As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY LIGHT SYSTEM NOT PASSING SYSTEM TEST. FAULT MESSAGES "ESPU115 VAC EMER L", "ESPU INT LOAD AFT L", & "ESPU UNIT EMERG L" ARE DISPLAYED. REMOVED AND DISPLAYED EMERGENCY POWER SUPPLY UNIT (ESPU) ON AIRCRAFT MID LEFT IAW AMM 33-51-38-400-001. OPS CHECKED GOOD.