What was found
PILOT REPORTED, "THE AUTOPILOT, AT TIMES, WOULD NOT JOIN THE LOCALIZER AND/OR GLIDEPATH. THE DAY I FLEW IT TO CONTOUR FOR MY ANNUAL, IT WOULD NOT HOLD A HDG HEADING AND KEPT POPPING THE CIRCUIT BREAKER." REPAIR STATION NOTES: OPERATIONAL CHECKOUT OF AUTOPILOT SYSTEM REVEALED THAT THE ROLL TRIM MOTOR WAS NOT OPERATIONAL. PILOT COORDINATED WITH OUTSIDE AVIONICS REPAIR STATION, AMI, TO TROUBLESHOOT AUTOPILOT 430 COMPUTER. AMI DISCOVERED THE AUTOPILOT COMPUTER WAS "FRIED" AND SENT OFF FOR OVERHAUL. OVERHAULED AUTOPILOT COMPUTER WAS INSTALLED AND ROLL SERVO WAS REPLACED. OPERATIONAL CHECKOUT GOOD.