What was found
PIT/LAN - FLT 4037 - EN ROUTE, BOTH OF THE FIRST OFFICER'S DISPLAY UNITS (PRIMARY AND MULTIFUNCTION FLIGHT DISPLAY UNITS) FAILED. DURING THE COURSE OF ACCOMPLISHING THE ABNORMAL FLIGHT PROCEDURES CHECK LIST, THE CREW DISCOVERED THE NR 2 INTEGRATED AVIONICS COMPUTER WAS INOPERATIVE. AIRCRAFT RETURNED TO PIT, LANDED WITHOUT FURTHER INCIDENT. PIT MX RERACKED THE NR 2 IAC COMPUTER IAW MM 31-41-00. GROUND CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.