As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHORTLY AFTER TAKEOFF FLIGHT, CREW REPORTED NR 1 EHSI (ELECTRONIC HORIZONTAL SITUATION INDICATOR) WENT BLACK, AND FLIGHT DIRECTOR AND AUTOPILOT DISENGAGED. FLIGHT CREW ALSO REPORTED AN ELECTRICAL BURNING ODOR. AFTER SEVERAL MINUTES, THE NR1 EHSI RETURNED TO NORMAL. FLIGHT WAS ABORTED AND THE ACFT RETURNED WITHOUT INCIDENT. R & R THE NR1 EHSI (WHICH DID HAVE AN ELECTRICAL BURNING ODOR) ALONG WITH THE NR 1 SYMBOL GENERATOR AND THE AUTO PILOT MODE CONTROLLER. ALL MX WAS PERFORMED IAW MFG INSTRUCTIONS AND A TEST FLIGHT WAS SUCCESSFUL.