What was found
DURING CLIMB, LEFT MAIN LANDING GEAR UNSAFE LIGHT REMAINED ILLUMINATED AFTER LANDING GEAR RETRACTION. RECYCLED LANDING GEAR AND LIGHT REMAINED ILLUMINATED. AIRCRAFT RETURNED TO ORD AND LANDED WITHOUT INCIDENT. UPON INSPECTION, FOUND THE LEFT MAIN LANDING GEAR UPLATCH MECHANISM BINDING. FREED MECHANISM, OPERATIONAL CHECK GOOD.