As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED THAT THE NR 1 AHRS UNIT FAILED IN FLIGHT. TROUBLE SHOT THE SYS & FOUND THE NR 1 AHRS UNIT DEFECTIVE, PN 7003360-943, SN 85090249. THE DEFECTIVE UNIT WAS REMOVED FROM SERVICE & A REPAIRED UNIT INSTALLED. OPERATIONS CHECKED OK.