What was found
WHILE EN ROUTE, THE FLIGHT CREW REPORTED THE NR 3 DISPLAY UNIT CYCLED ON/OFF TWICE. SHORTLY AFTER IT FAILED COMPLETELY AND THE CREW NOTICED A BURNING ELECTRICAL SMELL. THE CREW DECIDED TO DIVERT INTO DFW. DURING THE DESCENT, THE SMELL DISSIPATED. THE AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE WAS SECURED TO INSPECT AND REPAIR THE AIRCRAFT. TECHNICIANS REMOVED THE DISPLAY UNIT AND NOTED THERE WAS A CONSIDERABLE AMOUNT OF LINT AND DUST IN AND SURROUNDING THE COOLING APERTURES OF THE UNITS. THE LINT AND DUST WAS CLEANED, THE NR 3 DISPLAY WAS REPLACED WITH A REPAIRED UNIT AND OPERATIONAL CHECKS COMPLETED WITH NO DISCREPANCIES NOTED. THE AIRCRAFT WAS SUBSEQUENTLY RETURNED TO SERVICE.