As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
REJECTED TAKEOFF AT 30 KTS DUE TO LOSS OF ALL ELECTRICAL POWER EXCEPT EMERGENCY POWER. MULTIPLE PROBLEMS RELATED TO RAIN DRIPPING INTO AVIONICS BAY. REMOVED AND REPLACED NR 2 GCU AND ALL ASSOCIATED SYSTEMS OPERATE NORMAL ON ACFT, MM 24-41-11-4 AND 24-41-00-0.