As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A/C RETURNED TO GATE, FLT ATTENDANTS REPORTED STRONG ELECTRICAL ODOR IN F/C AREA. FOUND APU RELAY B9-607 WITH HEAT DAMAGE. SPLICED 12 INCHES NEW WIRE-RETERMINATED TERMINALS A2-B2-C2. REPLACED APU RELAY, BASE AND ELECTRICAL BUS TIE. ALL OPS NORMAL.