As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED SMOKE IN THE COCKPIT AFTER PACKS WERE SELECTED FOLLOWED BY PACK NR 1 OVERHEAT MESSAGE. THE ACFT RETURNED TO THE GATE. MX INSPECTED AND RELEASED ACFT IAW MEL PROCEDURES 21-51-00-3. MX REPLACED THE NR 1 PACK ACM. OPS CHECKS WERE GOOD.