What was found
THE NUMBER ONE REVERSER UNLOCK LIGHT ILLUMINATED IN-FLIGHT. THE AIRCRAFT RETURNED TO AND LANDED AT AIRPORT WITH NO FURTHER INCIDENT. MAINTENANCE FOUND THE UPPER LOCK ACTUATOR SENSOR BRACKET CRACKED. MAINTENANCE REPLACED THE SENSOR BRACKET AND AS A PRECAUTIONARY BOTH UPPER AND LOWER PROXIMITY SENSOR CIRCUIT CARDS. GROUND OPERATIONAL CHECKS WERE GOOD AND THE AIRCRAFT RETURNED TO SERVICE.