What was found
LAS - DIVERSION - FLT 790 - "S" - DURING CRUISE STANDBY HORIZON INDICATOR FAILED, AIRCRAFT DIVERTED TO LAS. MAINTENANCE REPLACED STANDBY HORIZON INDICATOR AND PERFORMED AN OPERATIONAL CHECK IAW T/C 34-22-24-04. AIRCRAFT CONTINUED TO PDX WITH OUT INCIDENT. BENCH TEST OF STANDBY HORIZON INDICATOR CONFIRMED FAILURE OF COMPONENT, THE FOLLOWING PARTS WERE REPLACED; THE LAMP, A SCREW, A PIVOT, 3 EACH BEARINGS, AND A REDUCTION GEAR. REDUCTION GEAR, P/N; H140ADY10, BEARING, P/N; A1186448.