As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT DECK AND CABIN FILLED WITH SMOKE. EICAS MSG FOR RIGHT RECIRCULATION FAN DISPLAYED. SHUTDOWN RIGHT AND LEFT RECIRCULATION FAN AS WELL AS GASPER FAN. SMOKE DISSIPATED AND CONTINUED TO LHR. FOUND RT RECIRCULATION FAN AT FAULT. REPLACED RT RECIRCULATION FAN AND NO FURTHER EVENTS OF SMOKE IN THE FLIGHT DECK OR CABIN HAVE BEEN REPORTED. PRELIMINARY SHOP TESTING FOUND BEARINGS SEIZED, THEREFORE PREVENTING FAN FROM TURNING.