What was found
BOS - FLT 2143 - EN ROUTE MHT-BOS, AFTER DEPARTURE FROM MHT, THE NOSE LANDING GEAR WOULD NOT RETRACT. WHEN THE LANDING GEAR HANDLE WAS CYCLED, THE LANDING GEAR RETRACTED NORMALLY. FLIGHT CONTINUED AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED PROXIMITY SENSOR 25GA. SYSTEM FUNCTIONALLY CHECKED NORMALLY. (M)