As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED ELECTRICAL SMELL IN COCKPIT AFTER ATTEMPTED APU START WHICH FAILED. INSPECTED APU AND FOUND STARTER GENERATOR TO BE MAKING LOUD NOISES AND SPARKING ON START UP. MAINTENANCE REMOVED AND REPLACED THE STARTER/GENERATOR IAW MM. GROUND RUN WAS COMPLIED WITH AND NO SMELL NOTED. (SW21200501803) (K)