As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF FROM SLC, SMELLED ELECTRICAL BURNING ODOR AND THE AIRPLANE FILLED WITH SMOKE. RETURNED TO FIELD. RAN BOTH PACKS IN AUTO AND MANUAL, WITH APU BLEED AIR AND ENGINE BLEED AIR. COULD NOT DUPLICATE DISCREPANCY. OPERATIONAL CHECKS GOOD.