As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING MAINTENANCE GROUND CHECKS THE MAINTENANCE TEAM DISCOVERED THAT THE ELECTRICAL EXTERNAL GROUND POWER WOULD NOT ENERGIZE AIRCRAFT SYSTEMS. TROUBLESHOOTING DETERMINED THAT THE GROUND POWER CONTACTOR RELAY WAS DEFECTIVE. REMOVED AND REPLACED WITH A NEW GROUND CONTACTOR RELAY P/N M83536-10-024L. OPERATIONAL CHECKS SATISFACTORY