What was found
FLT 4766 - DURING CLIMB-OUT FROM RDU-DFW, AT APPROXIMATELY 14,000 FEET THE CREW RECEIVED A RIGHT THRUST REVERSER UNLOCKED CAUTION MESSAGE. QRH PROCEDURES WERE COMPLIED WITH, AN EMERGENCY DECLARED AND THE AIRCRAFT RETURNED TO RDU, LANDING SAFELY. MAINTENANCE DEFERRED THE RIGHT THRUST REVERSER ON 12/3/2003 UNDER MEL NR 78-30-01. THE ABOVE DISCREPANCY WAS UNDER CONTINUED DEFERRAL WITH THE REPAIRS PERFORMED ON 12/5/2003 AND THE CORRECTIVE ACTION SHOWN ON MRR NR 03624, IN WHICH MAINTENANCE REMOVED AND REPLACED THE POWER DRIVE UNIT SHOWN BELOW AT THAT TIME. (M)