As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD INFLIGHT - CREW REPORTED AFTER GEAR RETRACTION RED LIGHT REMAINED ON FOR NOSE LANDING GEAR. ALSO REPORTED ADDITIONAL NOISE. IN COCKPIT, CYCLED GEAR BUT UNABLE TO EXTINGUISH RED LIGHT. EXTENDED GEAR WITH THREE GREEN LIGHTS. RETURNED TO ORD AND LANDED WITHOUT INCIDENT. REPLACED O-RING ON AIR VALVE AND ACCOMPLISHED COMPLETE NOSE STRUT SERVICE. SYSTEM GROUND CHECKED NORMAL OPERATION.