As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED SMOKE IN COCKPIT ON RAMP AND SUSPECTED PACK NR 1 TO BE THE ORIGIN. RAN ACFT WITH CREW, WITH PACK NR 1 OFF AND NO EVIDENCE OF SMOKE. MAINTENANCE R & R NR 1 AIR CYCLE MACHINE WITH OPS CHECK GOOD. ACFT WAS APPROVED FOR RETURN TO SERVICE.