As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PREFLIGHT INSPECTION THE FLIGHT CREW REPORTED THE APU GENERATOR WENT OFF LINE AND THEN THEY SMELLED SMOKE AND BURNT WIRES. MAINTENANCE INSPECTED THE APU AND FOUND NO EVIDENCE OF BURNT WIRING OR SMOKE. DEFERRED APU GENERATOR PER MEL 24-34-01-2.