As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED THAT DURING THE CLIMB AFTER TAKEOFF AT 28,000 FT THE COPILOTS AHRS SYS FAILED ALONG WITH THE AUTO PILOT SYS & YAW DAMPENER. THE CREW DIVERTED & LANDED. MX FOUND THE NR2 AHRS UNIT AS DEFECTIVE. THE UNIT WAS REPLACED WITH AN OVERHAULED UNIT, FUNCTIONAL CHECKS WERE OK & THE ACFT WAS RETURNED TO SERVICE.