As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA- NR 2 GCU FAILURE ON ENGINE START. START CONTINUED NORMALLY BUT RAMP PERSONNEL REPORTED SMOKE FROM GPU RECEPTICAL. INSPECTED AND FOUND BACKSIDE OF EXTERNAL POWER PLUG ASSEMBLY CRACKED. REPAIRED RECEPTICAL. NO PARTS REPLACED. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.