As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED. ATTITUDE PORTION OF INTEGRATED STANDBY FLIGHT DISPLAY FAILED IN CRUISE AND WOULD NOT RESET. FLIGHT RETURNED TO FIELD, NO EMERGENCY DECLARED. REPLACED ISFD WITH SERVICEABLE UNIT, IAW AMM 34-24-02. OPERATIONS CHECK GOOD.