As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED A BURNING PLASTIC ODOR & HEAVY AMOUNT OF SMOKE IMMEDIATELY AFTER TURNING ON BLEEDS AFTER TAKEOFF. ACFT RETURNED AND LANDED WITHOUT INCIDENT. MX INSPECTED AND FOUND NR 1 ACM TO BE AT FAULT. MX R & R NR 1 ACM. OPS CHECKED GOOD. ACFT APPROVED FOR RETURN TO SERVICE.