As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTS SMOKE IN CABIN WHILE SITTING ON THE GROUND WITH PACKS RUNNING. *S/D* THE COOLING FANS LOST POWER RESULTING IN PACKS GETTING HOT CAUSING A LIGHT HAZE IN THE CABIN WITH NO NOTICEABLE ODOR. THE PACKS WERE OPERATED OFF THE ENGINES AND THE APU TO VERIFY OPERATION. APU OP CHECKED NORMAL AND NO DISCREPANCIES WERE FOUND.