As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CABIN CREW SERVICE CHECK AND 3SV MX CHECK OF THE EMERGENCY LIGHT CHECK, CIDS MESSAGE EXT. LOADS AFT L. 2L DOOR EMERGENCY LIGHTS INOP. ALL EMERGENCY LIGHTS ARE INOP AND ALSO THE AFT OUTER LT WING EMERGENCY LIGHT. CHECKED POWER PACK AND LIGHT FOUND TO CAUSED BY THE AFT LT SLIDE. ALL OTHER EMERGENCY LIGHT CHECKS OK FROM MASTER EMERGENCY LIGHT SWITCH IN COCKPIT AND ARMING INDICATION ON DOOR PAGE NORMAL. REPLACED SLIDE ON SMB W-U E3387D, TESTED CID, OK, NO MESSAGE.