As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT DOES NOT ACCEPT EXTERNAL POWER. ACFT GROUNDED. CONFIRMED FAULT, ACFT WILL NOT ACCEPT EXTERNAL POWER. ACCOMPLISHED FIM 24-41, TASK 804, TROUBLESHOT TO DEFECTIVE "AC SYSTEM GENERATOR & APU MODULE" P5-4 PANEL. R & R P5-4 PANEL REF AMM TASK 24-21-51, GROUND FUNCTIONAL CHECK NORMAL REF AMM TASK 24-21-00-700-803.