What was found
DFW - FLT 1635 - AFTER TAKEOFF MSP, THE LANDING GEAR HANDLE WAS RAISED NORMALLY AND BOTH MAIN GEAR RETRACTED FOLLOWED BY AN MFDU MESSAGE NOSE GEAR UNSAFE. RECYCLED LANDING GEAR AND RAISED THE GEAR USING THE LANDING GEAR OVERRIDE SWITCH WITH ALL INDICATIONS NORMAL. AIRCRAFT PROCEEDED TO DFW AND LANDED WITHOUT INCIDENT. CLEANED NOSE LANDING GEAR PROXIMITY SENSOR AND ACCOMPLISHED LANDING GEAR PROXIMITY SWITCH ELECTRONIC UNIT CHECK WITH NO FAULTS NOTED. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)