As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD INFLIGHT T309/03FEB - NOSE GEAR WOULD NOT RETRACT. RECEIVED RED LIGHT INDICATION AND HEARD NOISE. CYCLED GEAR WITH SAME RESULTS. RETURNED TO ORD AND LANDED WITHOUT INCIDENT. SERVICED LANDING GEAR STRUT. SYSTEM GROUND CHECKED NORMAL OPERATION.