As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JFK - UPON GEAR RETRACTION CENTER HYDRAULIC PRESSURE LIGHTS AND EICAS MESSAGES ILLUMINATED. CREW DECLARED AND EMERGENCY AND REQUESTED TO LAND. AIRCRAFT RETURNED TO JFK WITH AN UNEVENTFUL LANDING. CAUSE OF PROBLEM WAS DETERMINED TO BE A LOOSE CONNECTOR ON THE AIR DRIVEN PUMP (ADP). THE CONNECTOR WAS SECURED WITH NO OTHER ITEMS.