What was found
DURING CLIMB OUT, AT AN ALTITUDE OF APPROX 160, EXPERIENCED A FAILURE OF ADI. AUTOPILOT DISCONNECTED AND DETECTED A NOXIOUS ODOR SIMILAR TO BURNING ELECTRICAL EQUIPMENT. RETURNED TO DEPARTURE AND LANDED WITHOUT INCIDENT. TROUBLESHOOTING REVEALED EVIDENCE OF A HIGH HEAT CONCENTRATION AT THE REAR OF THE ADI THROUGH VISUAL DISCOVERY OF MELTED PLASTIC OR PHENOLIC CAPS. ADDITIONAL TROUBLESHOOTING REVEALED THAT FUSE F2 WAS BLOWN IN THE NOSE AVIONICS BAY. ADI REPLACED, FUSE F2 REPLACE AND VERTICAL GYRO REPLACED AS A PRECAUTION. GROUND OPS CHECKS WERE PERFORMED ON THE SYS WITH NO FURTHER ANOMALIES NOTED.