As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: T/S MSG 33-51-38 EPSU EXT LOAD FWD L PER TSM 33-51-00-810-808-AUP TO STEP B. (2) (C). ELECTRICALLY CONNECTED NEW SLIDE ON FWD LPOSITION. FAULT CHANGED TO EPSU COMM FWD L (10WL). MAINTENANCE REPLACED EMERGENCY POWER SUPPLY UNIT 10WL (EPSU) TASK 33-51-38.