As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED LT THRUST REVERSER UNLOCKED MESSAGE IN FLIGHT. CREW RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. MAINTENANCE TROUBLESHOT, & FOUND A DIODE WITH AN OPEN CIRCUIT, REMOVED AND REPLACED DIODE TERMINAL BLOCK AND PERFORMED CHECKS MM. AIRCRAFT RELEASED FOR SERVICE.