As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO ORD, DUE TO LEFT OVERWING SLIDE DEPLOYED LIGHT AND OVERWING DOOR MESSAGE. A BROKEN HINGE AND IMPROPER LATCHING OF THE SERVICE DOOR AFT OF THE SLIDE COMPARTMENT ACTIVATED THE DOOR SWITCH, WHICH CAUSED THE DOOR OPEN LIGHT. REPLACED HINGE.