As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT RETURNED FROM TAXI REPORTING AN ELECTRICAL ODOR. FOUND APU GENERATOR FEEDER CABLE WITH A TERMINAL BURNED AT S3-23. THE CABLE WAS TAPED, APU DEACTIVATED, AND AIRCRAFT OPERATED DIRECTLY TO A MAJOR BASE FOR REPLACEMENT OF THE CABLE.