As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EPSU INTERNAL AFT L MESSAGE IS DISPLAYED AFTER EMERGENCY LIGHT TEST. FOLLOWED TSM 33-51-00-810-807-A, FOUND AFT LEFT EPSU AT FAULT. REMOVED AND REPLACED EPSU REF AMM 33-51-38. OPS CHECK GOOD. PARTS USED: 31-3350-9-9001,QTY :1 ROTABLE PARTS CHANGE WAS INDICATED - TT # 1918005 SN OFF 4893 POWER SUPPLY, C OFF 31-3350-9-9001 4893 ON 31-3350-9-9001 8307