What was found
GTF-ON FLIGHT NUMBER 2324, AFTER TAKEOFF FROM GTF TO HLN, UNABLE TO RETRACT GEAR. THREE GREEN AND 3 RED LIGHTS, NORMAL HYDRAULICS. COMPLIED WITH CHECKLIST, AGAIN ATTEMPTED TO RETRACT GEAR, THREE GREEN & THREE RED LIGHTS ILLUMINATED. FLIGHT RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. FLIGHT FERRIED TO PDX AND REMOVED AND REPLACED NOSE LANDING GEAR WOW NR 2 HARNESS. RIGGED NR 2 NOSE LANDING GEAR HARNESS SENSOR. PERFORMED OPERATIONAL TEST OF NOSE LANDING GEAR EXTENSION/RETRACTION SYSTEM. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.