As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 2414, JUST AFTER TAKEOFF, NR 1 ARCDU HAD A FAIL MESSAGE IN THE "INT" BOX. SYSTEM STAYED FAILED FOR ABOUT AN HOUR AND THE SYSTEM STARTED WORKING AGAIN. TURNING ARCDU OFF AND ON PER CHECKLIST HAD NO EFFECT AT TIME OF FAILURE. MAINTENANCE INTERROGATED CDS AND FOUND IOP 1 FAULT. REMOVED AND REPLACED IOP 1. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.