As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE STANDBY ATTITUDE INDICATOR FAILED IN FLIGHT. TROUBLESHOOTING FOUND THE STANDBY INDICATOR WAS DEFECTIVE. THE DEFECTIVE UNIT PN 501-1656-02 SN 1372 FAILED AFTER 194.1 HRS TOTAL TIME IN SERVICE. AN OVERHAULED UNIT WAS INSTALLED. OPERATIONS CHECKED OK.