What was found
SHORTLY AFTER TAKEOFF CREW NOTICED AN INCREASING TREND OF A BURNING ELECTRICAL SMELL. AFTER APROXIMATELY 15 MINUTES THE NR 2 PRIMARY FLIGHT DISPLAY FAILED WITH A "DISPLAY TEMP" FLAG. THE APPROPRIATE CIRCUIT BREAKER WAS PULLED, AND AIRCRAFT RETURNED TO KAPA WITHOUT FURTHER INCIDENT. MAINTENANCE VERIFIED THE FAULT AND FOUND LOW AIR FLOW TO THE NR 2 PRIMARY FLIGHT DISPLAY. AFTER REMOVING AN INK PEN FROM THE COOLING FAN AIRFLOW WAS BACK TO A NORMAL STRONG FLOW. THE NR 2 PRIMARY FLIGHT DISPLAY WAS REINSTALLED, AND OPERATIONALLY CHECKED GOOD. AIRCRAFT WAS RETURNED TO SERVICE.