What was found
PHX FLT 813 EN ROUTE CUN TO PHX. THE CREW REPORTS: STANDBY ATTITUDE INDICATOR GYRO FLAG IN VIEW. SAI TUMBLED, AND ACCOMPLISHED IMMEDIATE ACTION ITEMS SMOKE FIRE FUMES PROCEDURE IN QRH. SHUT OFF LIGHTS IN CABIN - UTILITY BUSS SWITCHES OFF: ELECTRICAL SMELL WENT AWAY. F/A NOTED HEAVY ELECTRICAL SMELL AT ROW 17. MAINTENANCE FINDINGS: FOUND INVERTER PROCESSOR FOR STANDBY ATTITUDE INDICATOR BURNED, AND STANDBY ATTITUDE INDICATOR FAILED DUE TO POWER SUPPLY FAILURE IN INVERTER PROCESSOR. POWER SUPPLY BURNED UP. REMOVED AND REPLACED SAI AND INVERTER PROCESSOR.