As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LHR - CREW REPORTED ELECTRIC SHORT IN SEAT 4D IS CAUSING ELECTRIC SHOCKS TO PASSENGER. DEACTIVATED SEAT 4D ELECTRICS. HANDSET DISCONNECTED, SEAT POWER AND SEAT CONTROLLER CIRCUIT BREAKER PULLED. REPLACED SEAT 4D. SYSTEM GROUND CHECK NORMAL OPERATION.