As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON START UP, CREW NOTED ADI ROLL MISMATCH ON #1 AHRS. CIRCUIT BREAKERS RESET, BUT PROBLEM REOCCURRED AFTER 2 MINUTES. AIRCRAFT POWERED DOWN AND AHRS RESET. PROBLEM SEEMED FIXED. ON ROTATION PROBLEM OCCURRED AGAIN. #1 AHRS REPLACED.