As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING AIRCRAFT BOARDING, A STRONG ELECTRICAL ODOR AND SLIGHT HAZE OF SMOKE BEGAN FILLING CABIN. ELECTRICAL BUS AND TRANSFER ABNORMALITIES ALSO OCCURRED. PASSENGERS WERE DEPLANED THROUGH MAIN CABIN DOOR WITHOUT INCIDENT. MAINTENANCE FOUND RIGHT PACK HEAT EXCHANGER FAN FROZEN. REPLACED FAN, OPERATIONAL CHECK NORMAL.