As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LHR - FLT 108 - EN ROUTE BOS-LHR - PASSENGER REPORTED ELECTRICAL ARCING UNDER SEAT AT 23C. SHUT DOWN SYSTEM AT MASTER SWITCH. LANDED LHR WITHOUT FURTHER INCIDENT. REPLACED ELECTRONIC BOX AT SEAT 23C. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)