As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND WIRE BUNDLE IN PIT BURNED. ALL CB'S IN PIT POPPED. CAUSE IS UNDERSTOOD AT THIS TIME TO BE A PRODUCTION SPLICE FOR A PDU SHORTED FROM MOISTURE, RESULTING FROM DIRECT CONTACT WITH THE BILGE INSULATION. REMOVED WIRES ARE BEING ANALYZED. REPLACED THE DAMAGED WIRES IN THE BUNDLE BY SPLICING PER AMM CHAPTER 20, AND RAISING THE WIRE BUNDLE UP OFF THE INSULATION BLANKET BY INCORPORATING THE INTENT OF BOEING SERVICE BULLETIN 777-25-0171.