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 2 AHRS WOULD NOT COME ON LINE (ATT AND HEADING FAIL). TROUBLESHOT AND FOUND THAT THE AHRS UNIT S/N 1113 FAILED. INSTALLED A REPAIRED AHRS UNIT. FUNCTIONAL CHECKS SATISFACTORY. NOTE: AHRS UNIT S/N 1113 FAILED 2.9 HRS AFTER INSTALLATION. THE 8130-3 INDICATED THAT UNIT WAS INSPECTED ON AUG 11, 2011.