As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED SLAT FAIL AFTER TAKEOFF FROM PHL, DECLARED EMERGENCY AND RETURNED TO FIELD AT PHL WITHOUT INCIDENT. MAINTENANCE TROUBLESHOT AND FOUND THE RT 3/4 SLAT HARNESS TO BE AT FAULT, AND REPLACED IT PER EMB AMM. A/C WAS THEN RETURNED TO SERVICE.