As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE LANDING GEAR FAILED TO RETRACT AFTER TAKEOFF. THE AIRCRAFT WAS RETURNED TO EWR WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE LANDING GEAR ACCESSORY UNIT IAW MM 32-09-121. OPERATION OF THE GEAR CHECKED GOOD.