What was found
LANDING GEAR HANDLE WOULD NOT RAISE AFTER TAKEOFF. ALL GEAR RED UNSAFE LIGHTS WERE ILLUMINATED. CABIN PRESSURIZED NORMALLY, FLIGHT RETURNED TO DTW AND LANDED WITHOUT INCIDENT. MAINTENANCE FOUND DEBRIS WEDGED BETWEEN FORWARD CABLE DRUM-C AND PULLEY GUARD FS74 AND CABLE RUN 103A AND 101A. REMOVED DEBRIS AND INSPECTED CABLES AND DRUMS, ALL CHECKED NORMAL. CONTROL LEVER OPERATED NORMALLY ON CYCLE.