As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAKEOFF UPON GEAR RETRACTION, RECEIVED A RED UNSAFE INDICATION ON UPPER AND LOWER PANELS. CYCLED GEAR AND GOT GOOD INDICATION ON BOTH PANELS. AIRCRAFT RETURNED TO THE SJU AIRPORT. REPLACED NLG UPLOCK BOX AS PER JIC 32-31-00. OPERATIONAL CHECK FOUND OK. (M)