As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MIA - EN ROUTE MIA-DFW NOSE LANDING GEAR WOULD NOT RETRACT. RETURNED MIA AND LANDED WITHOUT INCIDENT. REPLACED PROXIMITY SWITCH ELECTRONIC UNIT AND CLEANED NOSE GEAR UP SENSOR. CYCLED NOSE GEAR NUMEROUS CYCLES. SYSTEM GROUND CHECKED NORMAL OPERATION.